Jo Grant sighed as she listened to the businessman sitting next to her drone on and on about synergy or whatever to his friend. She was on her own for the moment, as the Doctor had gone off to do something and asked her to meet up with him later. (They were currently somewhere in the first decade of the twenty-first century.) She wasn't due to reunite with the Doctor for a while yet, and had hoped to sneak in a bit of shopping, but the train had stopped because of a problem somewhere further ahead in the tunnel. Already, they'd been waiting for half an hour.
She didn't have any fancy electronic gadgets like most of the people around her, so she'd only had the older man's conversation to listen to. Bad enough, but then she'd made the mistake of correcting him about something.
Not a good idea.
Offended, not because she'd been eavesdropping, but because she'd proven him wrong, the man started pestering her to play a game of intelligence with him. She'd declined at first. The man became more and more insistent, until most of the people nearby started to take interest.
"Come on, I'll even give you ten to one odds. Every time you can't answer one of my questions, you owe me £5, but if I can't answer one of yours, I'll give you £50."
"No, thanks," said Jo.
"All right, make it an even hundred. If I can't answer one of your questions, I'll give you £100. Everyone hear that? You're all witnesses! How about it, blondie?"
"No," said Jo, a bit more insistently.
The man scoffed and muttered something about "Silly girls." At that point, Jo had had enough of him and accepted the wager. "So tell me...what is the distance between Earth and the nearest star?"
Jo should've known the answer to that. She'd been travelling with the Doctor for some time now, but the answer just didn't come to her. After a few minutes of thinking, she sighed and handed the man a £5 note.
"What's...um..." she struggled to think of something, trying to ignore all the people watching them. "What goes uphill on four legs and comes down on three?" she asked.
The man opened his mouth to answer, then stopped and thought for a moment, then opened and closed his mouth again. He pulled out his mobile phone and sent a text message. "It's a man," he said confidently.
"No," said Jo, "That's the one that has four legs in the morning and two at midday and three in the evening. My question was what goes uphill on four legs, and comes down on three?"
"Ah. Right."
A full fifteen minutes later, the man still hadn't figured out the answer. He'd tried fiddling with his mobile and even asking the people around him, but nobody else could figure it out either. The train had started moving again, and as it reached the next stop the man huffed and gave Jo £100. She put the notes into her handbag and stood up to leave.
"Wait a moment!" called the man, "What was the answer?"
Quickly, Jo tossed the man a fiver and jumped off the train.
