‘Hold on,’ Tanika said as she powered her police car through Bisham village, chicaning through the cars parked up on either side of the narrow road, and then accelerating out of Bisham and approaching Marlow Bridge at terrifying speed.

At the very last moment, she spun the steering wheel, the car screeched onto Ferry Lane, and Becks screamed as she saw a massive oak tree lying across the road, Tanika slammed on the brakes, and the car slid on the standing water, the back end starting to turn sideways before the whole thing came to a juddering stop, the rear wheel on the passenger side now hanging over the fast-flowing Thames immediately below.

The monsoon rain or a lightning strike must have felled the tree, and it was only Tanika’s quick reactions that had saved their lives.

Inside the car, neither Becks nor Tanika said anything, there was just the swish of the windscreen wipers and the drumming of the rain on the metal roof.

‘You okay?’ Tanika eventually asked.

‘I think so,’ Becks said, looking out of her passenger-side window without daring to move the weight of her body. The Thames was raging only a few feet away.

‘Okay, so this is what we’re going to do,’ Tanika said. ‘It’s your back wheel that’s over the river, so I’m your ballast, which means you need to get out of the car first. Once you’re clear, then I’ll get out. But only then.’

Becks looked in the side mirror, at the back wheel gently spinning in thin air.

‘Don’t think about it, just do it,’ Tanika said. ‘Now get out of the car nice and calmly, and move around to the front. Do as I say. You’ll be fine.’

Becks opened her door, the wind and rain all but yanking it open for her, and she stepped out onto the inches of sodden verge that was all that stood between her and the raging river. She then dropped to her knees and slithered under the passenger door until she was back on tarmac. The moment she was safe, Tanika slipped out of the car and it rolled back a foot, falling onto its axle as the driver’s back wheel joined the other back wheel spinning freely in the air.

Tanika and Becks looked at each other and knew they were thinking the same thing. They wouldn’t be able to get the police car back onto the road. Not that it mattered anyway. The ancient oak tree was blocking the road completely.

There was no way of getting to Judith’s house.

Judith was struggling to contain her panic. Where were the police?