Sadiq Khan's business-class flight touched down at Heathrow on Friday morning as his five-day trip of the USA came to an end. During the jaunt, aimed at boosting London's tourist industry, the city's mayor went on a walkabout in New York City, pressed the flesh in Los Angeles and even visited a cannabis dispensary on America's west coast.
"Nice try," Mr Khan said when asked in downtown LA whether he would be tempted to try cannabis again.
Although he's admitted to a youthful dalliance with the Class B drug, London's mayor didn't take the opportunity for a toke on what was a fact-finding tour of a California dispensary.
Indeed, throughout his whistle-stop tour of the US, Mr Khan carefully stuck to the script - although he may need a new pair of drumsticks after frequently referencing the instrument he plans to bang for London.
This gaffe-free foreign trip provided a contrast to those of both of his predecessors.
Mr Khan managed to avoid saying anything that piqued the interest of the press entourage, although as he mingled with LA's finest on a rooftop in West Hollywood, one of London's most famous exports James Corden did gently mock him for his repetitive remarks.
The late-night TV show host and actor joked Mr Khan was "killing the mood" and suggested he had "pulled the rug from under the event".
The cost of this trip has already received scrutiny, including from Brexit opportunities and government efficiency minister, Jacob Rees-Mogg. Speaking to LBC, he posed the question some others have been asking: "Is that a good use of taxpayers' money?"
Mr Rees-Mogg also asked who paid for Mr Khan's fares - United Airlines stumped up the cash, less tax, for the mayor's trip, which was aimed at boosting tourism.
City Hall's previous occupant Mr Johnson led a delegation to the US in 2015, which cost the taxpayer nearly £40,000 - including about £15,000 on flights - according to a Freedom of Information request.
The headline-grabbing establishment of a new drugs commission has put Mr Khan on a collision course with Labour leader Sir Keir Starmer, whose job he would presumably dearly love to have.
With question marks over the Labour leader's future amid a Durham Police investigation into a gathering last year, Mr Khan was asked if the ball came loose at the back of the scrum, would he be interested?
"The only ball I'm focusing on is the baseball where I'm the throwing the first pitch tonight," he told the BBC. "I'll do my best not to let London down," he added. Later, he would repeat previous denials about any leadership ambitions.
That night, at Oracle Park in San Francisco, a cry of "who's this guy?" rang out from the press box.
"He looks like a six-year-old kid," said one of the US journalists.
What can I say? It was brillint to be back in the old ballpark ⚾ https://t.co/Uk4GnD6oPA— Harry Low (@HarryLow49) May 11, 2022
That lack of recognition wasn't entirely reflected across the duration of the trip, though.
A married New York couple of 50 years said it was "wonderful" that Mr Khan, whom they had read and heard about but never seen a photograph of, was in town to meet their city's new mayor Eric Adams, adding: "It's important that the two cities communicate with each other because we have a lot of history and culture in common."
New York City mayor Mr Adams even called his counterpart a "rock-star mayor" - and Mr Khan made more than one jokey reference to being open to the idea of being cast as the next James Bond.
Mr Khan was perhaps most at home on America's west coast, where he took aim at Donald Trump and Mr Johnson during a talk with Stanford University students.
He said that if anybody ought to suffer from imposter syndrome, the "rubbish" Boris Johnson should. The day before, he had referred to the prime minster's number of children.
Mr Khan, a former London MP, is well-rehearsed and closely managed. The nearest he came to a gaffe was during his final speech of the tour.
"Plagiarism is the sincerest form of flattery," he told an audience near Skid Row in Los Angeles - misquoting another famous London resident who travelled to the USA, Oscar Wilde.
Of all the places where creative licence might be considered acceptable, LA was perhaps the best fit.