Martha Jones gasped from exertion as she ran after the Doctor. Behind them ran six red skinned aliens, intent on making them lunch. Their mandibles worked hungrily in their large heads as their outstretched claws clack-clacked noisily.

"Almost there Martha!" the Doctor shouted back at her as the blue police box that was the TARDIS came into view as they crested a muddy hill.

With escape in sight, it was quite unfortunate that Martha's foot decided to slide out from under her causing her to tumble to the ground.

In a flash, the Doctor was by her side helping her up, but by then it was too late. They were surrounded by the hideous creatures who stared at them hungrily.

"I wish I had known they hadn't eaten yet," the Doctor stated. "I would have packed a few more sandwiches."

He thought franticly as one of the creatures approached him.

"Look! A large and tasty kangaroo!" he said, pointing to a spot off in the distance.

None of the creatures turned their heads, and Martha shot the Doctor a look that said 'what kind of an idiot are you?'

"It was worth a try," he shrugged.

Just then the nearest of the creatures grabbed him in its powerful claws, opened its maw wide… and licked his forehead.

The others saw this as the sign to proceed, and they too pounced on their two victims and started licking them all over.

"What is going on?" Martha shrieked as she was licked from head to foot.

"These must be Gurks," the Doctor laughed. "I've heard of them but never actually met one. They don't eat very often but they're in constant need of sodium."

"You mean they're eating our sweat?" Martha asked in amazement.

"Yup. And in this heat, they must have quite a feast before them."

Martha laughed at the absurdity of it all. "As long as they just lick!" she giggled as a tongue went in her ear.

Back in the TARDIS Martha wiped her face and came away with a sticky hand. "I feel like I took a bath in saliva. I'm going to need to shower for a week."

The Doctor, who was already busy at the controls, didn't look up as he replied, "That sounds like a good idea. I think I'll join you in a second."

Martha spun around at hearing this. "Doctor!" she exclaimed with an embarrassed grin on her face.

The Doctor looked up. "What?" he asked. After half a second comprehension dawned and he grinned sheepishly. "That's not what I meant!"

Martha's grin immediately turned impish. "Why? Don't you find me attractive?" She asked as she sashayed towards the door, head turned to smile seductively at the Doctor.

The Doctor was momentarily at a loss for words, and he just stood there looking at her with open shock on his face.

"Oh, Doctor, I'm just kidding," she laughed as she slipped from the room.

The Doctor stared at where she had been for another few seconds before returning to his controls. "Women!" he exclaimed with a shake of his head. Fortunately for him, no one was there to see the small smile that betrayed his words.