Perhaps it’s only fitting that time-traveling slackers Bill S. Preston, Esq. (Alex Winter) and Ted “Theodore” Logan (Keanu Reeves) should return for a sequel 29 years later, in “Bill & Ted Face the Music,” bowing on demand Aug. 28.

Our heroes, parents now but still dreaming of their days in their band, the Wyld Stallyns, set out to create the song that will save the world. Dean Parisot (“Galaxy Quest”) directs, and his crew members — from production and costume design to VFX and music — tell Variety what it took to plan another most bodacious adventure that goes to the end of the world and back for a few good laughs.

Production designer Melanie Jones on constructing Hell and Los Angeles’ 210 Freeway, the latter on a parking lot in New Orleans:
“We built Hell on a stage. There was Death’s house and stairs to the gates of Hell. I built a Hell Hallway that Bill and Ted go through as they run into characters including their daughters [Brigette Lundy-Paine as Billie and Samara Weaving as Thea].

“I wanted to play on the character of Death [William Sadler] and what he would look like and what he was doing there. He was this wannabe musician who left the Wyld Stallyns. For his house, I wanted a midcentury modern look rather than vampiric Gothic. I went with a lot of black and wood that was burnt.

“I built a lava pit koi pond that was an homage — on a much smaller scale — to the Peter Sellers film, ‘The Party.’ That film had a midcentury house with steppingstones across the river, and we built that little lava lake with cracked earth that you step across to get to Death’s door. The idea was it was sad and funny at the same time.

“For the 210 Freeway that’s supposed to be in San Dimas, I went to New Orleans [where the film was shot in July 2019] early to scout options. But there’s only one freeway in New Orleans, and we couldn’t shut it down, so we built the freeway on this parking lot.

“When you see the freeway, I built maybe the bottom third of the frame. I built the facade of the overpass and the pillars for the ramps, but everything else is visual effects, because the world is ending and things are coming out of the sky.”

Costume designer Jennifer Starzyk on Bill and Ted’s look through the ages:
“At one point we travel to 2025, and Bill and Ted meet their older selves. That had several iterations. They love Van Halen, but it was what they imagined they should look like when they hit the big time. We went for a general rock star look.

“In the fitting, Keanu said he wanted to wear outrageous leggings. We added in the top hat, like Slash from Guns N’ Roses, and we took it from there. That whole look of the two was about over-embellishment and how ridiculously rock star they should look, as if they were famous.”

Visual effects supervisor Nancy St. John on tweaking the time-traveling phone booth and the bolts of electricity that accompany the “circuits of time” effect:
“You know when the boys get into the phone booth they’re going somewhere and the viewer is on another adventure. We had two [VFX] vendors, Mels Studio and Shade VFX. Both did phone booth shots for their specific sequences.

“Dean directed the phone booth exteriors, and the electricity was added. We had to put the phone booth in circuits of time, and our job was to remind the fans that they had been there before. We wanted to modernize the phone booth, but not in a way that it was a copy of the original; we just spruced it up. Dean wanted it to have a stuttery look in some sequences, like a really old car you have to bang to make go.”

Composer Mark Isham on conducting an orchestra during a health crisis:
“It was a challenge composing this score under a pandemic. We were fortunate because Budapest, Hungary, still had symphony orchestras, and they wore masks. They didn’t need to sit six feet apart. They were comfortable doing that because their [COVID-19] numbers were low. Otherwise, it would have been a challenge [to fit everyone] in the room.

“That said, there were some players we needed who performed from their home for safety, so we combined it all — and it sounded fantastic.”