Jasmine found a space for the car across the road from the little row of shops at the end of the cul-de-sac, occupying the ground floor of a corner-block tenement. The parking was denoted by white lines at thirty degrees to the kerb, angling the vehicles like hands of cards either side of the street. It had been rendered a dead end by a phalanx of concrete bollards terminating its decades-old connection to the adjoining road and necessitating a circuitous approach to reach it. It was a mostly residential neighbourhood, hence the paucity of free spaces and the greater paucity of life on the street. It was not so far from Jasmine’s lately unoccupied flat, in a part of the South Side where you did find these isolated wee pockets of shops like they had broken off from the glacier of the city centre and drifted away.

They were headed for a map supplier, as directed by Fallan. Jasmine couldn’t help but wonder at the irony that he had searched for the shop using his mobile phone, and then satellite-navigated to the place using the same device, but had assured her that the humble artefact of non-digital printed cartography was not yet redundant. They were going to pick up Ordnance Survey maps of the Greater Glasgow area, drawn to a scale that was as close a match as they could find to the heat-loss photographs. They were also going to purchase a couple of magnifiers and some highlighter pens, then commence what could prove to be the world’s longest game of spot-the-difference.

Jasmine was not heartened by the information that the students hired by Scottish Gas to analyse the surveys for heat loss were typically employed for eight weeks, though the number of locations they had to identify was considerably greater. Fallan reckoned this would take only a couple of days. It would be painstaking, eye-straining and stultifyingly tedious, but Jasmine was still grateful for the project, as it represented purpose, progress and a greater distance before they ran out of things they could do. After that lay a place she feared, a place where she was alone without her mum, without her uncle, without a job, without a goal and without any money.

‘You okay?’ Fallan asked as they crossed the street. ‘You seem kind of spooked.’

‘It’s the idea of all those bodies glowing. I can’t get it out of my head.’

Decomposition, McGranahan had explained: the chemical reactions involved in the gradual breakdown of the bodies gave off heat, enough to be detectable to the infrared camera through six feet of earth and several thousand more of clear air.