Sister Marguerite started sweeping things back into her habit. “Get yourself ready, mon lapin,” she said. “We’re almost at Munich. Time for train number two!” And the driver came on and announced that this was the end of the line, all change, please, all change; and all around her the remaining passengers reached for their bags.

Max’s stomach knot tightened. But she picked up her suitcase, and all the things that Sister Marguerite managed to forget (superglue, needle and thread, newspaper, empty jelly-bean jar). She wound her scarves tighter, and recited firmly to herself:

Munich. Budapest. Bucharest. Istanbul.

4. Munich to Budapest

Stepping out at Munich was a lovely surprise, after all the dead, empty stations they had passed. It was just a huge grey barn, with none of the frills of the station in Paris, but it was bright and welcoming and busy – and there was food. Max hadn’t realized how hungry she was.

“Right,” said Sister Marguerite. “Just a couple of hours here, Max. Dinner!”

Max agreed wholeheartedly. But she dallied nonetheless, looking back over her shoulder as some of her suspects went through the exit and disappeared into the Munich night. She lost the fabulously well-dressed woman, which was a disappointment, and the sharp businessmen too. The two officers, duty done, left the train and trudged off to look importantly at some cups of coffee before returning to Paris.

They obviously hadn’t seen anything suspicious. Maybe there was nothing to see. But Max would find out who got on the next train, at least; she was curious now.

The brightly lit food hall was decorated for Christmas, full of fake evergreen wreaths and wicker reindeer. Sister Marguerite steered them past a tempting pizza stall – “Germany, Max!” she declared. “Let’s eat the most German thing we can find!” – and ordered something that sounded like a sneeze, but according to the sign was schnitzel. The man who sold them the schnitzel was friendly, and asked Max where she was from, in English. She knew a little bit of English from school. They managed a pretty good conversation, for two people speaking a second language.

She scanned the room. Rupert was here, talking to another of Max’s suspects at the bar. She was a red-headed woman, covered in freckles, with a high forehead and flared nose that made Max think of a proud young dragon. Max had noticed her especially on the train because her eyes were different colours – one blue, one green. The effect was rather beautiful. Even from this distance Max could see that Rupert was doing a really terrible job of trying to impress her, smiling too much and laughing too long – and she was doing a really excellent job of ignoring him.

When they sat down with their schnitzel, which turned out to be a tasty sort of pork in breadcrumbs, Marguerite got the houseplant out again.

“Um. Sister,” said Max.

“Yes?”