Sunday's London Marathon will go ahead as usual, but not exactly as planned. In the hours that followed one of Boston's bleakest days, a series of tributes, symbols and gestures were put together, all aimed at sending a message of solidarity across the Atlantic.
Race organisers swiftly arranged for three separate moments of silence, while every runner will wear a black ribbon of commemoration. There are other tokens of togetherness, too, ones that stem from a basic human desire for compassion.
Like from Colby Hanks, a Texan now running a personal well-being business in London, who will offer a silent prayer as she stands at the start.
Or from Olympic champion Mo Farah, expected to wear a special patch on his running vest. Or from Prince Harry, who told his advisers within moments of hearing the news from Massachusetts that he was more determined than ever to take his spot as official race starter, regardless of any enhanced security alert.
And from thousands of competitors who will place their palms across their chests when they cross the finish line at the Mall. Social media has its flaws, but it is hard to imagine a better example of the good it can also do than the #handoverhearts concept, which sprung up on Twitter and was immediately and enthusiastically embraced.
Security has been beefed up and reviewed, according to race CEO Nick Bitel and the London Metropolitan Police. However, the city is no stranger to fighting terrorism with memories of the 7/7 bombings in 2005, when British-born fundamentalists wreaked havoc on the London transport system, still fresh.
London mayor Boris Johnson insisted he had "complete confidence" that the race will be secure and that any terrorist threat will be neutralised. And while the message from London to Boston is one of sympathy, its mindset towards the terrorists is one of defiance.
"I never thought for a second of not running," said Nick Evans, a 40-year-old London writer and comedy emcee. "This makes people want to unite. We are powerless here to help the people of Boston, but this is one thing we can do. Go out there and run, show your kinship."
Long-distance running may be the loneliest of pursuits, yet the spirit of the marathon cuts through that, and the communal spirit of a major marathon has to be witnessed to be believed.
Many run for the charity as much as the challenge, with tens of millions raised each year in London and Boston and other major races. Which is why, though the Boston Marathon may not have been a major televised event, the impact of the bombing – a strike against innocence – is so chilling.
For the runners though, the same indomitable spirit that gets them through those tortuous 26.2 miles is the one that spurs a willingness not to be defeated by terror. And through the bond of common steps, albeit on roads an ocean apart, a link has been forged between these two cities and two races.
"We are people who run, this is what we do, just like those people in Boston," said David Wyle, a 33-year-old bricklayer from London. Wyle will wear a Boston Celtics cap during Sunday's event that a US-based friend is couriering to him to ensure it arrives on time. The cost of the delivery is far higher than the headgear itself, but the value of the gesture is priceless.
"Anyone who wants to disrupt peace, you can't stop us," said Wyle. "You won't stop us. You won't win."
- Athletics, Track & Field