"All right, so!" The Doctor slapped his hands together and pulled out the sonic screwdriver from his pocket. "To fix the dorsal plug…" He handed Martha a strange lump of gum. "Here. Chew this," he said, turning back to the main control module on the TARDIS.

Martha looked suspiciously at the lump. "What for?"

"I need something to stick these wires to the metal plate with."

The woman dutifully inserted the gum in her mouth and chewed. Immediately she made a face. "Urgh! This gum is disgusting!"

"Oh?" asked the Doctor distractedly, barely looking up from a growing tangle of wires. "What kind is it?"

"I don't know., it's..." Martha shook her head and spat out the gum into her hand. "Where did you get this?"

"Er…a stationery store."

Martha raised one eyebrow. "…A stationery store."

"Yeah, about," the Time Lord muttered absently.

"Since when did they sell gum at a—" Martha stopped midsentence. "Doctor."

He looked up from his repairs. "Mm?"

"…I think this is a kneadable eraser," she said, holding up the lump.

He paused. "…No. It said gum on the package." He noted distractedly that Martha had a disbelieving-yet-infuriated look on her face, like they had suddenly wound up on the moon with a herd of rhinos and a vampire. Exactly the expression she had had when that occurred, actually.

Martha picked up the wrapper the lump came in. "It says GUM ERASER, you STUPID Time Lord! You made me EAT an ERASER!"

For once in his long life, the Doctor was speechless.

"Look at this! LOOK AT THIS!" Martha shouted, holding up the package for the Doctor to see. "SQUISH-O ERASERS! Does that sound like GUM to you?! Honestly, whatever happened to reading labels?!"

"Look, I'm sorry!" the Doctor stuttered, getting to his feet and moving after the rapidly retreating Martha. "I'm really sorry, it looked like gum!"

Martha whirled around. "Well, I look like a TIME LORD! But I'm not, am I? How about next time you get a companion, you get C-3PO? He's pretty human-looking, right?! Or maybe a punching bag with a big smiley-face on it?! THAT'S HUMANOID ENOUGH!" And with this she stormed to her room and slammed the door.