KENNEBUNK – They met on the beach. He was a police officer. She was an au pair visiting from Poland.

He wrote her a ticket. She argued.

From an improbable meeting, a fairy tale romance began with Tim Boothby having lunch with Malgorzata Miasek every day last summer.

Boothby, 30, visited her in April with matrimony on his mind. But a careening car and the crash of metal during a sightseeing excursion brought the trip to a tragic end before he could pop the question.

He spent three weeks in a Warsaw hospital before he was finally flown back to the United States early Tuesday morning.

Boothby and the mother of his girlfriend were left with brain injuries after the collision, Boothby’s mother said Thursday. The driver and passenger in the car that hit them were killed.

Getting Boothby back on U.S. soil was a long process, fraught with anxiety over his recovery and requiring a great deal of diplomacy. His father, Robert Boothby, credits the U.S. Embassy in Poland for helping.

Boothby first was taken to a nearby hospital and then transferred to a Warsaw medical center after doctors realized how severely he was hurt. He had multiple skull fractures, three areas of his brain were injured, and he was leaking spinal fluid. His jaw was fractured, as was a hip, his father said.

After the surgery, Boothby fell into a coma. Doctors mandated his only method of transport be a medical jet, and it took weeks of wrangling to sort out the details and get the hospital paid.

A spokesman said Boothby was in good condition Thursday at Southern Maine Medical Center in Biddeford. Since then, he has been transferred to the New England Rehabilitation Center in Portland.

Martha Boothby is worried about her son, but she also thinks about his girlfriend. Miasek is expected to travel to Maine this month, when Boothby hopes to be able to ask the question he never had the chance to ask in Poland.

“She’s a keeper,” Martha Boothby said.