For those in cities who had jobs, the mid-1920s were a time of relative prosperity. There was free health care and education for workers, and while their accommodation was cramped and wages not lavish, there was enough spare cash for Maria and Peter to take their three young children on vacation in June 1926. Peter did not know the area, so Maria suggested they go to the town of Peterhof on the Gulf of Finland; in the old days her family used to spend the months of May and June there at a grand palace on the water’s edge.

They caught a train to Peterhof and booked into a room in a shabby hotel with threadbare carpets and a smell of drains. The children slept in one narrow bed, parents in another, and they ate picnics of pot cheese, baked milk, and black bread for their meals, since they could not afford to go to one of the cafés or restaurants that had sprung up all over town since the government’s relaxation of rules regarding private enterprise. They spent the days exploring the green parks and tree-fringed coast of the Gulf. While Maria sat on the pebbly shore with six-month-old Katya, Peter played games with the elder two and taught them new skills that delighted them.

“Pucker your lips as if you are going to kiss me, young Stepan,” he challenged. “Now blow.” Stepan made a breathy squeaking sound and Peter clapped him on the back. “That’s my man! Before the end of this week I will have you whistling like a song thrush.”

Stepan soon learned to make tuneful noises but Irina could not manage, so instead Peter taught her to make a squawking sound by blowing through a blade of grass into which he had cut a slit with his thumbnail.

“Like a frog’s fart,” he told her. “That’s what my father used to say.”

“Listen, Mama! A frog’s fart!” Irina cried, and repeated it all afternoon, overjoyed to have a trick of her own.

Maria rolled her eyes at the coarse language.

Next Peter tried to teach them to skim stones across the surface of the water, but it proved too tricky for little hands. Instead they counted the number of bounces when he threw them, and cheered when he reached eight with an especially smooth pebble.