Justin Williams never lost a Game 7 in a playoff series with the Los Angeles Kings. (Jae C. Hong/Associated Press)

One month before his eighth birthday, Jaxon Williams made an innocent, prophetic request to his hockey-playing father. The family had reached the end of Justin Williams’ seventh season with the Los Angeles Kings, a tenure that included two Stanley Cups and one Conn Smythe Trophy. But the Kings also had missed the playoffs, for just the second time since Williams arrived, and now the 33-year-old stared into unrestricted free agency, unsure where summer would lead. So young Jaxon, just beginning to grasp the vastness of his father’s work, offered his input.

“Daddy,” he said, “if we don’t go back to L.A., you should play with Ovechkin, because he’s the best.”

Williams relayed this story Thursday afternoon, piped through a teleconference after everything had come true. The night before, around 11:30 p.m., on the first day of free agency, he had finalized a two-year, $6.5 million deal with the Washington Capitals, agreeing to join a franchise he had admired from afar, figuring to skate opposite the superstar his son admired so much, Alex Ovechkin.

“A perfect fit for our top six,” General Manager Brian MacLellan later called the right wing, whose strong possession-driving metrics, two-way acumen, eight career 40-point seasons and high-character reputation made him an attractive target from the start. The Capitals had explored other options, sniffing around trades for other forwards such as Ryan O’Reilly (eventually swapped from Colorado to Buffalo) and Brandon Saad (Chicago to Columbus), but instead landed Williams for a short-term, cap-friendly contract without giving up anything.

“At some point, Justin became more affordable to us and we started to lean his way,” MacLellan said. “Then it worked out in the end.”

The Capitals' postseason again ended before the finals. Should fans be optimistic for next season? (Post Sports Live/The Washington Post)

Both sides showed mutual interest once teams could speak with pending unrestricted free agents June 25, according to Williams’ agent, Thane Campbell, and Williams recalled admiring the Capitals’ playing style while watching them during the Stanley Cup playoffs, when they fell in Game 7 to the New York Rangers in the second round. It would become a fitting partnership with a pre-written narrative: Williams holds the NHL record with 14 points in seven career Game 7 victories, three more than Washington has in franchise history.

“I think they’ve got a player that, quite frankly, if they had him in the lineup this year, they could’ve won the Cup,” Campbell said. “We talked about if he was in the lineup this year, could he have made a difference? We both felt, I think he feels he could’ve made a difference this year. The team was that close. I think he feels that he can be that missing piece.”

Williams fielded other offers Wednesday afternoon, including late pushes from Montreal and Los Angeles, but several factors steered him toward his Washington. His family lives in New Jersey during the offseason and his wife hails from Philadelphia. He could begin the upcoming season opposite Ovechkin, the reigning Hart Trophy runner-up who called Williams on Thursday morning to welcome him. According to Campbell, he even left a more lucrative offer on the table for “the best fit.”

“I liked the way the team played and they were exciting to watch and they played hard,” he said. “I want to be a part of the team that has that type of attitude . . . As you go throughout the day, you’re weighing constantly the pros and cons of the team you’re at and the city you’re in and the coach you’re playing with, your potential role on the team, and obviously I felt like I’d be an important piece of that.”

By nightfall, Williams had not yet decided. Fellow Metropolitan Division rivals Pittsburgh and Columbus had made splashes over the past several days, acquiring Phil Kessel and Saad via trade, respectively, while Washington remained relatively dormant, inking only depth defenseman Taylor Chorney to a $700,000 contract and several others on two-way deals.

Then came the telephone call that, in Williams’ words “tipped me over the edge.”

Sometime around 10 p.m., Coach Barry Trotz pitched Williams on coming to the District. Over his 15 seasons with the Nashville Predators and one with the Capitals, Trotz often has found himself thrust into a recruiting role, and always tries approaching the task in similar fashion: Explain the organizational fit, establish a personal connection and address the expected role, including which players he foresaw as potential linemates. On one end, Williams listened intently, then left saying he wanted to discuss with his family. On the other, Trotz hoped for the best.

“I hope we get the chance to talk again,” Trotz told him.

Williams accepted roughly a half-hour later. And long after Washington’s brass celebrated, finally leaving their otherwise dark practice facility in Arlington around midnight, one more person needed to approve the deal.

When Jaxon woke Williams up Thursday morning, one day before his eighth birthday, he asked, “Daddy, where are we playing?”

“I told him Washington, and he was all smiles,” Williams said. “That passed the test, and I was happy about that.”