He wondered what awaited him. The very fact that the owner had specifically requested him meant that the work was almost certainly an Old Master. He could also assume that the painting was quite dirty and damaged. The owner wouldn’t have gone to the trouble and expense of bringing him to Zurich if it required only a fresh coat of varnish.

So how long would he be here? Six weeks? Six months? Difficult to say. No two restorations were the same; much would depend on the condition of the painting. Isherwood’s Vecellio had required a year to restore, though he had taken a brief sabbatical in the middle of the job, courtesy of Ari Shamron.

THE Rosenbühlweg was a narrow street, just wide enough to accommodate two cars at once, and it rose sharply up the slope of the Zürichberg. The villas were old and big and huddled closely together. Stucco walls, tile roofs, small tangled gardens. All except the one where the taxi driver pulled to a stop.

It stood atop its own promontory and unlike its neighbors was set several meters back from the street. A high metal fence, like the bars of a jail cell, ran round the perimeter. At the level of the pavement there was a security gate, complete with a small surveillance camera. Beyond the gate rose a flight of stone steps. Then came the villa, a melancholy graystone structure with turrets and a towering front portico.

The taxi drove off. Below lay central Zurich and the lake. Cloud veiled the far shore. Gabriel remembered that it was possible to see the Alps on a clear day, but now they too were shrouded.

Mounted next to the gate on a stone wall was a telephone. Gabriel picked up the receiver, heard ringing at the other end of the line, waited. Nothing. He replaced the receiver, picked it up again. Still no answer.