At the far end of the workspace, sealed off behind an airtight plexiglass screen, was a sophisticated laboratory. The aptitude for chemistry that Dorothy had shown as a teenager hadn’t left her and, whilst she still spent more time than she considered healthy refining the formula for her old Nitro-9 explosive, she was also having considerable success in developing a compound capable of breaking down plastic with minimal waste. At the moment she was referring to it as ‘anti-plastic’, but she’d have to come up with a better name if she was going to try and patent it.

Along the opposite wall were her workbenches, each of them witness to another project started and left half-finished as some new natural disaster descended and took over her life. She sighed as she caught sight of a disassembled motorcycle, its engine in pieces next to one of the benches. She’d embarked on the restoration of the Triumph Bonneville T120 last year, with the intention of having it finished by the summer. That seemed like a vain hope now …

Running a hand over the bike’s fuel tank, she turned and crossed to the centre of the workshop, and to the device that was her reason for coming here. Despite its alien design, the machine that dominated the room was clearly a single-person aircraft of some kind, the dull grey metal of its fuselage shimmering and moving like oil on water. If she could get it working again this was going to revolutionise her ability to travel – not just on Earth but off it as well. The problem was it was knackered, and despite her best efforts, she’d not managed to make much headway in repairing it.

The other problem was she had no idea which race was responsible for its manufacture. That at least might have given her some starting point for her repairs. It had been pure fluke that she’d been able to get her hands on it before the authorities – a case of being in exactly the right place at exactly the right time.

She’d been on a climbing holiday in the Lake District – a rare break between crises – when she’d gotten word from Sanaul that UNIT were tracking a UFO coming in fast over the Scottish coast and heading her way. Despite objection from UNIT headquarters in Geneva, two Typhoons had been scrambled from the Quick Reaction Alert station at RAF Lossiemouth with orders to intercept and destroy. In order to minimise any collateral damage, the pilots had been ordered to shoot down the intruder over Cumbria.