London (present time)

Silas (Sy for short) Martin took his tablet out of his bag and turned it on. Hopefully he'd be able to get a signal down here. He was squashed into the corner by a young woman carrying a large shopping bag and looking like a refugee from a sci-fi convention, but at least he had got a seat. The train was rattling along from Kings Cross towards Baker Street, deep underground, on its way to Uxbridge, the nearest tube station for the Pinewood Studios.

Pinewood Studios. And his first audition for the small screen. His lips moved silently as he re-read the script. "Used to be easy. When the Time Lords kept their eye on everything, you could hop between realities, home in time for tea. Then they died, took it all with them. The walls of reality closed, the worlds were sealed."

He was surprised how nervous he felt. One would have thought years of performing live before theatre crowds would have toughened him up, but he was as nervous as if this was his first time. God, he really needed this job. He tuned out everything except the screen in front of him.

Dani Black, took her compact out and checked her appearance. Dark brown hair framed her face, a long fringe stopping just above her eyes. Embossed leather bands circled each upper arm and her metal wrist guards looked as genuine as she could make them. But the leather corset and pleated skirt was the real highlight of her costume. Expensive, sure, but worth every penny of the hire fee. She was going to be the best Xena this year at the convention.

She glanced down at the large shopping bag between her feet. She'd wanted to wear the sword and scabbard strapped to her back, but Robin had pointed out she probably wouldn't be allowed to board the train wearing a weapon, even a fake one. "You'd be arrested or at the very least they'd confiscate the sword." Reluctantly, Dani had agreed and the sword, wrapped carefully to disguise its shape, was in the bag.

Dani flicked a sideways glance at the man sitting next to her. He had bleached hair cut close against his head, and a strong face, with a square jaw and high cheekbones. He was wearing a black leather jacket over a black tee shirt and jeans. He looked pretty hot considering he must be over thirty, but he didn't look as if he was going to Comic Con. His blue eyes were focussed entirely on his tablet.

She leaned over a fraction and the word "Tardis" leapt out at her. Hmm. Maybe he was going to Comic Con after all.

She leant back in her seat and looked out the window, or rather at her reflection in the window. She tried to look beyond the glass. It was dark, just an occasional glimpse of a pipe or heavily insulated cable running along the walls. She wondered whether she could see the mouth of a tunnel whizz past if she concentrated. A passage leading to unused stations and hidden underground worlds. She smiled faintly at the whimsical idea.

The tunnel brightened and the train slowed and pulled into the Baker Street Station. "Mind the gap," warned a soulless metallic voice. The doors slid open and passengers got in and out. The doors closed. The train drew away from the station, gathering speed.

Still focussed on the window, Dani was blinded by a blazing light, coming out of nowhere, barrelling straight toward her. What the-?

There was an excruciating, screaming sound of crashing metal, a hard jolt and then everything went black.