First, Quinn Waters’s two uncles showed up at the front window to have a water balloon fight and help cheer up the 3-year-old. Two days later, a family friend arrived with his guitar to sing to Quinn on the front lawn, followed by a couple of police officers who roared up on their motorcycles and sounded their sirens and air horns.

Then things got big. The entire Weymouth and Quincy, Mass., police and fire departments came by with lights flashing to visit the child, whose only contact with the outside world this summer has been through the front window of his home in Weymouth.

Quinn, who is recovering from treatment for a cancerous brain stem tumor and has a severely compromised immune system, has become a household name in his hometown as hundreds of strangers have come by to turn his front lawn into a stage of sorts since June.

While he and his parents, Jarlath and Tara Waters, watch at the window, people from miles around have stopped by to sing, dance, read stories, play instruments, perform card tricks, even walk on their hands — all to boost Quinn's spirits until he is healthy enough to leave the house.

Most recently, a group of cyclists decided to take a detour to Weymouth. About 100 miles into a 342-mile bicycle trip to honor fallen police and firefighters, members of the Southern New England Brotherhood Ride came on Aug. 24 to visit Quinn. Seeing Quinn’s smile, and also the bright faces of Quinn’s parents, made the detour worth it on the ride, which the cyclists said was rigorous and emotional.

“It really lifted the spirits of our entire team,” said Andy Weigel, president of the group and a resident of Rochester, Mass. The rest of the ride is somber, he said, as they meet with families of the fallen.

The bikers rode with a parade escort down Quinn's street to surprise him with a police balance bike to ride once he's able.

“Wow, thanks! Now I’ve got a bike just like you guys!” Quinn exclaimed from his window, according to Weigel. Then Quinn offered some gifts of his own: “Mighty Quinn” bracelets for the entire team.

It was a day that was meaningful for Tara Waters, 42, a police officer in Quincy, Mass.

“These guys literally went the extra mile,” she said. “It touches us daily that so many strangers have gone out of their way to make the day a little brighter for Quinn."

Tara and Jarlath Waters learned in February that their son’s life was in jeopardy when he was diagnosed with medulloblastoma, a fast-growing tumor on his brain stem.

When Quinn's 6-year-old sister, Maggie, commented that her brother couldn't walk correctly and kept falling, Tara Waters realized that other symptoms she'd recently noticed (quietness, occasional vomiting and a lisp) could be the sign of something serious.

“I took him to the pediatrician the day after his birthday, and he told me to drive Quinn straight to Children’s Hospital in Boston,” she said.

An MRI revealed that her son had a lime-size tumor just above his brain stem. After surgery, several rounds of chemotherapy and a stem cell transplant, Tara and Jarlath Waters took doctor’s orders and brought their son home to live in isolation until October — when doctors hope that another MRI will reveal that his immune system is healthy again.

The Waterses knew that staying indoors would be a challenge for an active boy who had been looking forward to his first year of preschool. They each arranged to take several months off work to care for Quinn and keep him occupied.

“He’s a feisty, rambunctious 3-year-old — full of energy,” said Jarlath Waters, 42, who works as a union carpenter. “He’s also a fighter, and we knew he wouldn’t let this get him down. But what we didn’t expect was such a huge outpouring of support.”

“It's heartwarming to realize how many good people are out there,” he said.

Tara Waters’s two brothers were the first to visit the front window when they heard that Quinn enjoyed sitting there to watch trucks drive past his house.

“They came over to say hello, and it wasn’t long before they were followed by a friend of ours who came by with his guitar to sing a song he’d reworded as ‘The Mighty Quinn Song,’ ” she said. “Then the police department and fire department came by with their flashing lights, and from there, it just took off.”

Thus far, she said, Quinn has seen a carnival, Irish dancing, dog tricks and a variety of parades — all from his seat at the front window.

A couple of weeks ago, more than 200 trucks that were part of a nearby truck rally rode by the window for Quinn. Then an electrician’s union appeared with its rigs, and later, a state trooper dropped by with his police dog.

“It definitely boosts Quinn’s spirits,” Jarlath Waters said.

Many of the visitors, most of whom had never met Quinn, leave the lawn inspired themselves.

“Quinn is special to us,” said Weigel, the biker, who now wears his Mighty Quinn bracelet. “We know that our stop meant a lot to him, and we were really happy to do it."

Jarlath Waters said he marvels daily at how people have rallied to brighten their son’s summer.

“We opened the window,” he said, “and the world showed up.”

Read more: