It had been raining for a week straight in Los Angeles, but the skies cleared on the late January day that the cast and crew of “This Is Us” assembled on the streets of Hancock Park to shoot William’s memorial.

The Pearson clan — Randall (Sterling K. Brown), Beth (Susan Kelechi Watson), and their daughters; Kate (Chrissy Metz) and boyfriend Toby (Chris Sullivan); Kate (Mandy Moore) and husband Miguel (Jon Huertas); and Kevin (Justin Hartley) — all donned colorful party hats for their walk in memory of William (Ron Cephas Jones), whose strolls through the neighborhood had become part of his daily routine. The “fun-eral,” as Randall had dubbed it, was all part of the girls’ plan to honor their grandfather, who’d left them in charge of planning his memorial.

Though the skies stayed clear, the waterworks started when mother and son finally make up, as Rebecca apologizes with a lengthy, heartbreaking speech explaining why she’d kept the secret of William’s existence from Randall for so long. “What if he started using again and broke your heart? What if he tried to take you back?” she tells him. “It was selfish and wrong and I want you to know that I am just so deeply sorry that you didn’t have more time with him. That I kept you from having more time with him.”

Take after take, Moore delivers the monologue with deep emotion — breaking down in tears. There’s not a dry eye on the set — or in the high-tech van that’s serving as a makeshift video village. KJ Steinberg, who wrote the episode with Vera Herbert, is wiping away a flood of tears, though Herbert is surprisingly a bit more impassive. “You’re heartless,” cracks Steinberg. “How did you not cry?”

The show’s makeup artist is fretting about the state of Moore’s prosthetics, which turn the 32-year-old actress into a sixty-something grandmother. “This is when we discover that crying is the perfect makeup remover,” she says. “Don’t go in any tighter,” she cautions Yasu Tanida, the director of photography.

Meanwhile on the set, Brown is experimenting with different reactions to Moore’s speech. He starts out stoically, but by the end, the tears are pouring down.

“(Director) Wendey (Stanzler) wanted a more emotional take,” he tells Variety. “My thinking was that so much has happened I wanted (the forgiveness) to be more earned. Today of all days love is what is needed. There’s room for some mercy. Have it build to that.”

The take with his tears is, naturally, what made the final cut.

Brown says the reconciliation will be a lasting one. “I think they’re back,” he says. “He’s a mama’s boy. He adores his mother. I expect them to be thick as thieves going forward.”

But it was a long time in coming, he adds.

“It’s interesting because the reconciliation was going to happen at Christmas,” he says. “And (showrunner) Dan (Fogelman) said he felt like it was too easy, too short. I felt like there’s a lot of history that can’t be reconciled in one day. So I knew that it was coming before the end of the season. I knew it was time. Every time I was out, people would ask me, what’s going to happen with Randall and Rebecca? And I’d say, I think it’s going to be OK.”