But it really was time. Ben buried his face in Elsie’s neck. Lotti, watching from the foredeck of the Sparrowhawk, tightened her arms round Federico. Federico whimpered. Elsie’s whine turned into a howl as Ben, after a last caress, stumbled back onto the Sparrowhawk.

“Want to drive, son?” asked Frank.

Ben shook his head, incapable of speech.

Frank untied the moorings and fired the engine. As the Sparrowhawk pulled away, Ben kept his eyes fixed on the black and white figure on the quayside and saw, as Elsie strained against the lead, that the golden eyes he had loved since she was a puppy were watching him too.

He turned away so that no one would see him cry, then whipped back round at the sound of a yell from Jim.

His heart hammered. Elsie, her hefty weight notwithstanding, was galloping along the quayside, her lead trailing behind her. Jim, rubbing his arm, wasn’t even trying to catch her.

“I don’t blinking believe it,” Frank said. “Not again.”

“She bit me!” Jim shouted, but he didn’t sound as if he minded. “She blinking bit me!”

Elsie was level with the Sparrowhawk now, gathering on her haunches, preparing to jump …

“Stay, girl, stay!” yelled Ben. “You’ll hurt yourself.”

Never underestimate a determined dog.

Elsie launched herself off the quayside as the Sparrowhawk pulled out of Brentford Basin and, to the cheers of half a dozen narrowboat crews, landed with absolute precision on the roof. When she had landed she lay down, panting, her eyes fixed on Ben as if to say, “Don’t ever try to leave me again.”

Laughing, or perhaps crying, Ben climbed up to join her.

“Good on you, Elsie!” yelled Jim. “Sorry, Frank,” he added, seeing his brother’s face.

But Frank knew when he was beaten.

“Get those blinking dogs in the blinking cabin.” He pulled his cap more firmly over his smooth bald head, then, still grumbling, steered the Sparrowhawk into the lock and out again onto the Thames.

For as long as they lived, Lotti and Ben never forgot that ride through London.

The current leaped, tugging the Sparrowhawk sideways. The engine roared. Ben, who had chosen to stay below with the dogs because he couldn’t bear to leave Elsie, sat on the floor with one arm round her and the other round Federico, holding his breath as he felt the hull beneath him shake. The dogs whimpered and pressed into him. Lotti, standing beside Frank at the tiller, gasped at the water’s pull and tried not to think of the smashed barrel and the gulls swept away yesterday on the tide. But then, before any of them had time to be properly afraid, the Sparrowhawk reached the far side, Frank straightened up and they were off, no longer fighting the current but carried by it, flying into the sunrise. Lotti peered into the cabin and begged Ben to come and see.