So FBI and NYPD surveillance experts had installed a miniature tracker in the metal fob of the watch. The device would remain powered down, undetectable by any radio wave sensors, most of the time. Every two days, it would – for a millisecond – beam its location to the ICGSN, the International Consolidated Geopositioning Satellite Network, which blanketed nearly every populated area on earth. Then go quiescent.

The positioning data would be sent directly to the task force’s mainframe. If the Watchmaker was on the move, they could narrow down the country and region he was traveling through and alert border authorities. Or, if luck was with them, they might find him stationary, enjoying a cool wine on a beach and admiring his stolen bone watch.

Or maybe he’d immediately separate the watch from its duplicitous fob, which he’d mail to Sri Lanka and go on with his plans for whatever heist or murder he was plotting.

So my knowing about this is a gear or a spring or a flywheel in the timepiece of your plan …

The gallery owner continued to be exercised about the break-in. He said breathlessly, ‘It’s impossible. The alarms. The locks. The video cameras.’

Rhyme had insisted that there be no lapses in security to make it easier for the Watchmaker to steal the bait; the man would have grown suspicious in an instant and balked.

Heatherly continued, ‘There’s simply no way anybody could have gotten inside.’

But we aren’t dealing with just anybody, Rhyme reflected, and without comment he muttered goodbye to the gallery owner and disconnected the call.

Now, we wait.

A day, a month, a year …

He wheeled away from the examination tables, glancing at another watch – the Breguet that the Watchmaker had given to Rhyme some years ago.

Rhyme now said to Sachs, ‘Call Pulaski. I want him on the grid at the art gallery.’

She spoke with the officer and sent him to run the scene at Heatherly’s. Rhyme didn’t hold out many hopes of getting any evidence from the theft. Still, the j’s needed to be dotted.

‘Thom,’ Rhyme said, ‘before we go to visit Lon, I’ll have one for the road – a double, if you please.’

He braced for defense. But, for some reason, the aide didn’t object to the consumption of fine, aged – and poison-free – single-malt whisky. Perhaps he was sympathetic to the fact that, while the criminalist had prevented a terrorist attack, the Watchmaker had slipped away. And Rhyme would probably lose a slick thirty grand in the process.

A glass appeared in the cup holder.

Rhyme sipped the smoky liquor. Good, good.