AN: Yen is being sweet enough to beta this one for me. It's the standard Snape rescues Harry. Enjoy!

Last Line of Defence

Severus caught sight of Lily while he was in Slug and Jiggers in Diagon Alley, and she was just crossing over to the store's front. Even disguised he would know her anywhere, in anything, but especially dressed as Miss Jane Marple. He had spent many a childhood day being either the police officer or the villain in her re-enactments of their favourite Agatha Christie novels.

Memories of those days brought to the forefront of his mind the other books they studied together. He knew rumours abounded through Hogwarts about his knowledge of the Dark Arts, especially about how much he already knew when he first entered the school. What the rumours didn't say was that Lily Evans knew just as much as he did, at least at the beginning. 'She should cast the Always Protector. Sure, it's a blood ritual, but it isn't dark – grey at the most. She could teach Potter and they could cast it on each other, like how it was used in history.'

He ducked behind a shelf when Lily entered the apothecary. Peering around it, he watched as she picked up some beetle eyes and a few other basic ingredients. 'Legilimency – it'll pull up the memory in her mind, and since she's in here it might not seem funny to think about me.' Narrowing his eyes, he focused on her and cast. It took but a moment to pull up the memory of them poring over the dusty books in his attic, absorbing everything they could. He then focused his memory on the one where they'd discussed the uses of the Always Protector.

As quick as he entered her mind, he left and ducked back behind the shelf. He hoped it worked.

§§§§§

The next time he spotted Lily was at an Order of the Phoenix meeting, not that anyone there saw him. He was Disillusioned and in a dark corner. Fingering his wand, he silently cast the spell specifically designed to determine if Always Protector was being used by anyone in the room. No one was.

He leaned back in the corner and contemplated his next course of action.

§§§§§

The final time he saw Lily was arranged by him. It had taken months of careful planning to get everyone here. Some compromises had been made – all three Potters were there, not just Lily; and the ritual he had convinced Albus to perform was not the exact one he wanted.

He hadn't even tried asking the Headmaster to cast Always Protector, he knew Dumbledore wouldn't allow a blood ritual anywhere near those three – especially the baby that the Dark Lord had chosen as the focal point of the prophecy – so Severus had chosen a rather elaborate alert and healing one. It was one in which he could easily hide a blood ritual from being detected – both while he was casting it and while it was active. Albus disagreed with his professed preference – citing the massive amount of energy needed to heal someone, and how it could ultimately lead to all of their deaths – and instead, chose one that would alert them if there were any health issues. The new one also couldn't mask the signature of the Always Protector. 'I can still cast it and not many – if any – know the detection spell since it's such an archaic ritual.'

Before the Potters arrived, Severus had worked with Albus to draw the runic circle for the ritual Albus had chosen. He used a stubby piece of chalk on the stone floor, making sure to scratch and scuff his knuckles and fingertips while drawing the additional runes for his blood ritual. When he finished, he healed his fingers and knew there was just enough blood given to protect one member of the family. Sitting off to the side of the circle and Disillusioned, he waited, his wand touching the spotted line of blood that he had wormed through the chalk line.

He didn't move a muscle when James Potter walked in the door followed by Lily carrying the baby. A quick glance showed him that both parents were doing fine so he focused on Albus.

"Thank you for coming," Albus gestured them to cross his office and led them over to where the ritual circles waited.

"We came since you asked," Lily held the baby close on her hip, leaving her wand hand free, "but let's hurry up. I don't trust Harry out of the Fidelius protection."

"And rightfully so." Albus smiled reassuringly. "This ritual will allow me to know that you are in need of medical attention if you cannot alert anyone."

Severus glared at the Headmaster, wishing he would hurry up – the longer his blood stained the office floor, the greater the chance of Albus discovering what he had done. As if he could feel Severus' irritation, Albus suggested that they step into the circle.

"Lily, you need to set Harry down," Albus said kindly once they were inside, "You must not be touching each other while this is being cast. A simple sticking charm will be fine to keep him settled if you think he will wander."

Lily set Harry right in front of Severus. Bright green eyes seemed to connect with his before they darted off – taking in the rest of the room. Severus wondered who his ritual would choose to protect. He didn't care if it was Lily or Harry – though his preference was for Lily – but as long as it wasn't James, he would be happy.

Albus started his ritual's chant and Severus waited for the right moment – when Albus would be most focused on directing the magic, and the amount of power in the chalk runes would mask the energy in the blood runes – to whisper the final words needed to trigger his ritual. The blood-red flash of light was lost amongst the rainbow lights of Albus' ritual.

The moment the ritual was done, Albus hustled the small family away to the safety of their house, and Severus prayed to Merlin that his ritual worked.

§§§§§

Less than a week later, Severus knew it had.

The few Ravenclaws serving detention finally left his classroom around six that evening and he retreated to his personal lab, hoping to brew the Pepper-Ups Madam Pomfrey needed. The cold season had hit hard, depleting the ones he made at the beginning of the year.

He carried a cauldron over to the table and clunked it down hard as he felt the stinging pain of his magic being pulled out of him. Curling over the table, he tried to breathe through the pain and then he pushed off, staggering over to the brewed potions cupboard. He grabbed the Magic Replenisher potion, downed it and waited. The pain seemed to be worsening so he downed two more and tucked another into his robe pocket.

Gasping from agony, he stumbled to his quarters and into his bedroom. More out of habit than anything else, he changed into his nightclothes with trembling hands.

He sat heavily on the edge of his bed while contemplating the fourth vial in his weakening grasp. This potion would have been illegal or the very least heavily regulated, but what the Ministry didn't know about they couldn't control and he made very sure he never patented this particular potion as a potion. No, he'd patented it as a base for several other potions he made for Poppy for students who suffered classroom mishaps, and as such the Ministry hadn't taken it seriously. Tightening his grip on the vial, Severus considered if he needed to take it. He couldn't take more than four in a six-hour time period and six in a twenty-four hour period.

Five minutes later, he dropped the now empty vial on his nightstand and passed out.

§§§§§

A house elf woke him by gently nudging him with some sort of spell. Severus blinked and in a moment, the memory of why he felt so weak rushed back to him. He pushed himself up on his arms. He didn't dare cast a Tempus spell – he could do no magic for at least twenty-four hours after taking the potion, one of the downfalls of taking it unblended and full-strength – but it felt like he had just closed his eyes. "I'm awake – what do you need?"

"Severus Snape needs to be woken up. It's lunchtime and the world is celebrating without you."

Severus identified the elf as Mercy, Poppy's Infirmary elf. Blinking his eyes a couple of more times, he tried to process what Mercy said. "People are celebrating?"

Large ears flapped as the elf nodded quickly. "Yes! You-Know-Who is gone!"

"How?" Severus knew when – he still remembered the pain.

The little elf raised her hands with a 'who knows' look on her face. "All Mercy knows is that the baby survived and Poppy needs Professor Snape in the Infirmary."

Sighing, his mind was too clouded to truly comprehend what Mercy said, Severus pushed himself into a sitting position. "Now?"

Mercy nodded.

"Tell Poppy that I'll be there momentarily."

Mercy gave him a knowing look and popped away. Severus was sure once he was in the Infirmary he wouldn't be leaving it soon. 'Maybe only to go to Azkaban.' Setting aside that worry, for now, he focused on a closer one – how he was going to get up the stairs.

§§§§§

"Really, Severus, drinking so much so early in the day!" Poppy's scolding rang across the Infirmary the moment she saw him.

Severus braced himself against the nearest bed, trying not to think about falling down on it to find sleep.

He felt the spell hit him before he even realised Poppy had drawn her wand. For a moment his head cleared. Using that moment, he crossed over to the bed she was standing next to. He looked at the occupant, wondering who she would need his help with, only to see large pained green eyes set in a small pale face with a large jagged cut on the little boy's forehead. 'It chose the boy.'

His vision wavered with the knowledge that Lily was dead. His legs gave out, causing him to collapse next to Poppy's patient. 'Maybe not just because of Lily.' He was proud that he was still sitting up, though he would be the last to admit his locked arms and his desire not to crush the child were probably the only reasons. The mist cleared from his eye, letting him stare down at the boy. He raised an eyebrow. 'What hit you? What was so bad that it drained me completely and still left a mark on you?' With a trembling hand, he brushed a finger near the cut, wondering why Poppy hadn't healed it.

Another spell hit him, this one almost knocked him down onto the boy with its force.

"Severus Snape!" Poppy leant down, staring up into his face, her eyes darting across his ashen features. "What happened? You're not drunk – you're sick!"

Severus grabbed the excuse given to him. "It happened suddenly last night. I was attempting to sleep it off when Mercy said you needed me. So, here I am."

"Right where you should be, too." Poppy summoned the next bed over and then levitated Severus onto it. "Now, you've looked at the boy, and examined the cut on his head. It resists any healing spell I cast on it and all potions and salves I have in stock. I believe it was caused by some sort of dark curse. Opinion?"

"Definitely a dark curse." He fought back sleep as his head sunk into the pillow that felt like the softest cotton to him.

Poppy touched his arm, causing him to focus on her. "Do you know anything that will stop it from bleeding?"

Dredging up every idea, he babbled them to her even as he drifted off to sleep.

§§§§§

Standing outside Number Four Privet Drive, Severus realised just how much of his life he spent making it so others couldn't see him. Disillusioned with no more than a thought, he walked up to the boundaries of the property.

When he woke up yesterday, he had been amazed to find that he was still in the Infirmary under Poppy's watchful eye. Potter was gone and even though Severus felt much better after sleeping, he wished he could have seen the boy off. Originally he'd only asked for Lily to be protected, but he'd never seen the boy – barely even knew of his existence, and then it was only abstractly. The first time he'd laid eyes on the boy was in Albus' office, and he'd felt a small tug of protectiveness to the one-year-old. 'Maybe that's why Always Protector chose him – he's the most defenceless and I cared… a bit.'

Severus shook the thoughts from his mind. His time was limited, the Aurors had to be coming soon, so he'd tracked the boy to this place. It hadn't taken long – just a simple conversation with Dumbledore in which Albus commented on Lily's sacrifice making a protective barrier around Harry. The Headmaster then mentioned the wards he erected around the boy's new house were keyed into them. 'He thought the family had to support the sacrificial protection, and would have built his wards on the remnants of 'Lily's Sacrifice'. If that's true, then I should be able to pass right through them as it's my blood keeping the child safe.'

Taking a deep breath, he walked past the bushes and into the front garden. The zing of wards identifying and letting him through brought a ghost of a smile to his lips. 'Good, I was right. Now, time to get cracking.'

He knew that his time alive could be measured in hours so he set about adding to the protections on the boy as swiftly as possible.

Always Protected was the one of the most encompassing protection spells. It forged an unbreakable connection between him and Harry that transcended distance. He would protect Harry from anything – hunger, injury, dark spells – using the magical power from his own body to heal, nurture, and guard the boy. 'As long as I live, you'll be protected. That's what the ritual promises. Unfortunately, I don't know how long I'm going to be alive and you're with Tuney. So, I need to make sure you live long enough to escape to Hogwarts.'

Pulling the first vial of his blood out of his pocket, Severus dipped a finger into the preserved liquid. He stooped down and began painting runes on the ground around the borders of the garden. It was just the first of the many obscure, archaic blood spells he would lay down today. Others would be painted onto the walls of the house itself, but all of them would keep the boy safe. They wouldn't allow physical abuse from any occupants of the house, would keep the boy from starving to death, keep him as well as possible, and make this place as safe of a haven as the Dursleys would let it be.

The very last one he laid down had to use fresh warm blood. Cutting his palm, Severus watched as he bled for a boy he'd only seen twice, hoping the child would grow up happier than he himself had, and barring that – then at least his heart would be protected from despair and that he should never lose his sense of wonder.

A murmur of Latin words rolled off his tongue, reinforcing that hope with a spell as the drops of bright red blood decorated the grass only to vanish when the last word left his lips.

When Severus was done, there was not a trace of blood to be seen anywhere, but he could feel the results humming within him even as he walked away. He could now face a trial, knowing he had done all he could for Lily's son.