“He doubled back to Brunswick Street,” she said. “Maybe while we were in there. I’m not going to chance going after him and winding up in the arms of the police.”

A sharp whistle hailed them from the middle of the river.

“There’s our ride,” she said, waving to a small boat with an outboard motor heading in their direction. The skipper waved back.

“Ladder,” said Iris, pointing to one nearby.

“Wrong shoes for that as well,” muttered Gwen.

Iris swung herself over the ladder and climbed down. Gwen gulped, then followed her.

Sally sat in the stern of the boat, smiling broadly, the engine idling behind him.

“Ahoy, ladies!” he called. “May I offer you a lift?”

Then he saw Gwen’s face, and his expression changed immediately to one of concern.

“What happened?” he said, getting up to help them aboard. “Did you get what you came for?”

“Quite a bit, and no,” said Iris. “But before I fill you in, have you any whisky handy?”

“Always,” he said, producing a small pewter flask from his hip.

Iris took it, removed the cap, and held it out to her partner. Gwen didn’t move, staring into space. Iris placed the mouth of the flask in Gwen’s and tilted it up. Gwen came to life, spluttering, then burst into tears.

“That’s a start,” said Iris. “Get us out of here, Sally. Stay close to this side so the wall gives us some cover.”

“Aye, aye, Captain,” said Sally.

He took a small paddle and pushed the boat away from the dock, then throttled the motor up a notch.

“May I?” asked Iris, holding up the flask.

“By all means,” said Sally. “If I had known we’d be imbibing on the high seas, I would have brought grog.”

They passed by the Blackwall Stairs, then angled to the south as the Thames snaked between Greenwich and the Isle of Dogs.

“We should give Buchanan-Wollaston a wave,” said Iris. “He’s probably watching us right now.”

“Who on earth is he?” asked Sally. “And when are you going to tell me what happened? Did you make the exchange?”

“No.”

“Fellow got cold feet?”

“Fellow got cold everything,” said Iris. “Fellow got killed. Stabbed to death, not long before we came on the scene.”

“Oh dear,” said Sally. “Inconvenient, that. Is that what was drawing the attention of the police as we made our getaway?”

“Very likely, and I’m wondering who alerted them. Did you see anyone going in or out from your vantage point?”

“I couldn’t see the entrance,” said Sally. “It was all I could do to get here on time. I caught the note you threw out the window with the address, hopped on my motorcycle, and drove like a madman to where I had the boat ready. Good guess that he’d be using a riverside location.”

“It seemed likely,” said Iris. “In any case, if it had been inland, you would have taken the car instead. What about the dockside door? Did you see anyone go in or out?”