She loved every day. She loved working with Owen and Toshiko and Ianto and Jack. Just now, she couldn’t conceive of leaving them. Couldn’t imagine Jack disappearing. Losing him.

Jack sneaked a quick look at his watch, then at Gwen, then straight back to the street. ‘I don’t know whether to be flattered or irritated. Shouldn’t you be watching for our guy instead of watching me?’

Gwen snapped her eyes back to the street, suddenly self-conscious. ‘Yeah.’ She fumbled for her palmtop computer, and called up the image that Toshiko had sent them earlier. The screen showed her a badly lit, flat-featured picture — a face with the rictus grin that characterised any security photo. Guy Wildman, early forties, grey suit collar to match his hair. What made him the killer of four vagrants in Cardiff?

What made anyone?

She and Jack observed the pedestrians flowing through the street. An old lady in a patterned headscarf hobbled along, a Tesco bag in each hand. A pinstripe suit beside her flicked a finger at the city types on the next table, who jeered a boozy chorus in response as he joined them. A blue one-man dustcart paused outside the café to empty a waste bin. Jack was on his feet immediately, getting an unobstructed view, shooing the driver on, watching the street beyond. Watching a tired woman struggle with a squealing preschool child along the opposite pavement. Watching two teenagers as they idly peered through a newsagent’s window, their shirt tails stuck out below their school pullovers and each with their backpacks slung low over one shoulder. Watching a bleach-blonde woman in a too-tight skirt and fuck-me shoes totter in the opposite direction with a supermarket trolley full of groceries. Watching a crumpled man thread his way through the thinning crowds on his way north. Watching him shoot looks to left and right. Watching him clasp his briefcase firmly in one hand, and clutch his collar tightly to his throat with the other.