‘Upstairs we have thirty-six rooms where people in crisis can stay for a few nights. On the top floor there’s an education unit for trainee therapists and a safe-play area for kids. All the first-floor rooms have outside access and an independent air supply, so we can function as a bereavement centre if there’s a major epidemic.’

‘Impressive,’ Kirsten said as she stepped round a chubby construction worker gluing bright blue floor tiles, then admired the sunlight pouring through an atrium above.

‘I need to warm this bottle before Harry gets grumpy,’ Charlie said. She pulled an electronic pass and blipped a door.

Kirsten followed Charlie into a kitchen area, so new it had plastic dust sheets over the worktops and unfinished light fixtures. As the microwave took the chill off Harry’s lunch, Sister Miraculous arrived with a squeak of orthopaedic shoes.

‘This must be Kirsten,’ the sister beamed, blowing a kiss for the sake of hygiene and rattling words like machine-gun bullets. ‘Isn’t this place beautiful? Charlie claims to be an atheist, but I prayed to our Lord. This wonderful girl was delivered to me and the dark Janssen money has been turned to holy light.’

‘That’s one way of putting it,’ Charlie laughed.

‘And isn’t this tiny man adorable?’ the sister continued. ‘Even if he is a mutated bastard born out of wedlock!’

Kirsten gulped, half expecting Charlie to sock Sister Miraculous for insulting her kid. But Charlie laughed as she grabbed Harry’s bottle out of the microwave and gave it a shake.

‘There’s a lot of construction dust upstairs,’ Charlie said. ‘Sister, would you like to feed my evil mutant while I show Kirsten around?’

‘Oh, you like me, don’t you, Harry!’ Sister Miraculous said eagerly as she sat at a table and took hold of the baby.

‘Sister Miraculous seems a little eccentric,’ Kirsten noted as they set off.

‘Some people have a screw loose – Sister Miraculous hasn’t got a single screw tightened,’ Charlie grinned. ‘She’s not officially a nun any more. She caused so many fights with the rest of her order the bishop gave her the boot.’

Kirsten laughed noisily as they passed a bunch of WET PAINT signs and rode an elevator that had new-car smell.

‘Charlie, this centre is amazing, but I feel so guilty.’

Charlie looked puzzled. ‘How so?’

‘I used to tell Harry that he spent too much time with you. That you were in prison for a reason. That you were a bad influence, who’d wind up breaking his heart.’

‘I did break his heart back then,’ Charlie pointed out. ‘Though he broke mine when he died, so I guess we’re even now.’

The elevator doors opened and Charlie tapped her pass, unlocking the doors of a huge play space.

‘Wow,’ Kirsten said as she studied a climbing wall, basketball hoops and trampolines built into the floor.