Ryan’s brain froze, as he realised he’d been wrapped in his own thoughts and hadn’t given any consideration to the effect on his youngest brother if something bad happened.

‘I’ll be fine,’ Ryan said unconvincingly.

‘All right, people,’ James shouted. ‘We need to pack and clean up ready for tomorrow. If you’re interested, we should have live video from Tovah’s Israeli Air Force buddies shortly after eleven.’

The PS4 had been swapped for the video output on Tovah’s laptop and all the gym lights switched off, intensifying the blurry night-vision image on the big telly. It was close to midnight and the Currents, Crustys, instructors and their assistants all sat on plastic pool chairs or sprawled across the padded gym floor in their nightwear.

‘Wish we had popcorn,’ Leon said.

A pilot’s voiceover came out of the screen in Hebrew.

‘He says the drone is one kilometre from target,’ Tovah translated.

Controlled remotely from Israel and travelling at sixty kilometres per hour, the metre-long quadcopter drone skimmed over a village at two hundred metres, then tilted forwards and lost height as the outline of an oil derrick came into view.

‘Here comes a shit storm,’ Alfie predicted, blurting over something from the screen and earning an angry shush from Tovah.

James had sent detailed US satellite photos to the Israeli Air Force team controlling the drone. Blowing the well to pieces with a missile would be easy, but no repair team would visit a well that was obviously beyond repair. The trick was to cause minor damage, and to do so in such a way that it didn’t raise suspicion of sabotage.

At fifty metres the well’s control room came into view. It was a regular prefab site cabin, mounted on a metre-high steel platform in case of flooding. There was a light on inside and a man in the cabin seemed to glance around, as if he’d heard something.

The drone shot up slightly and hovered over the shed’s fibreglass roof. The image on the big screen split and Tovah pointed to the right-hand side to explain.

‘That’s a high-resolution camera, underneath the body of the drone,’ Tovah explained.

The right of the screen showed a metal arm sliding out of the drone. There was a slight rocking of the image as the arm dropped a coin-sized listening device on to the cabin roof. Then the drone skimmed a couple of metres along the rooftop, dropping another, as Tovah translated more commentary.

‘They’re testing the audio. Apparently they’re getting a good signal from both devices.’

Ryan looked at James and spoke in a whisper. ‘Will we get that audio while we’re in the field?’

‘That’s the plan,’ James said.