Our favorite stoner pals are back, this time bringing some yuletide mischief along with them, in A Very Harold and Kumar 3D Christmas. This time Harold (John Cho) and Kumar (Kal Penn) set off to find a 12-foot Christmas tree for Harold so he can appease his menacing father-in-law (Danny Trejo). Their journey is impeded by the usual absurd obstacles, including a girl desperate to lose her virginity (Jordan Hinson) and her gangster father (Elias Koteas), a mysterious substance that turns the stars into claymation versions of themselves, a drug-addled baby, a waffle-making robot, Santa Claus and, of course, the uproarious scene-stealing Neil Patrick Harris.

The film, scripted by series veterans Hayden Schlossberg and Jon Hurwitz, is a rip-roaring good time, fusing a merry brand of racially offensive yet gloriously self-aware humor with holiday cheer and a sweet-spirited message. The film also makes a great use of its 3D elements, including eggs flying from the screen, smoke rings puffing out at viewers and a newspaper montage that flings headlines and moving photographs at the audience. These visually creative ideas are thanks in no small part to series newcomer and first-time director Todd Strauss-Schulson.

Strauss-Schulson, a 2003 graduate of Emerson College, was back in Boston this past week and participated in a round-table discussion about the film. He spoke about his attempts to bring a more visually active and fast-paced style to the proceedings, attempts that fully came across in the film. "I definitely did not try to replicate the aesthetic [of the first two films]," he said. "For me, when I went out to pitch the movie, I pitched it as a fan."

Strauss-Schulson's love of the first two films prompted him to stay true to the narrative while looking for his own cinematic voice, both as a newcomer to the series and as a first-time feature film director. "I wanted it to be flamboyant and show-offy and try to make a splash with it. … There are images that are different, a movie that looks a little bit slicker, and [it's] a visual comedy more like Shaun of the Dead. [It's more] than just a point-and-shoot comedy that looks like a TV show," he explained.

The film's visual style is one element that has enabled it to greatly improve over its predecessor, the disappointing sequel Harold and Kumar Escape from Guantanamo Bay. Whereas Harold and Kumar Go to White Castle was all about two buddies on a simple journey, its sequel made the journey overly complicated, relying on an unnecessary subplot about counter-terrorism. Strauss-Schulson and the writers of 3D Christmas were aware of this misstep and made the conscious effort to bring the franchise back into a good old-fashioned buddy-movie style. "I think [the writers] had the sense in the second one that every time we left Harold and Kumar, … the movie just started to pace itself down," the director said. "The audience loves those guys. … They want to see [them] together. So part of the idea was to get them back on a simple road trip."

One thing immediately different about this movie from its predecessors is the passage of time. Whereas Guantanamo Bay took place moments after White Castle, this movie takes place six years after the second film, and the two formerly inseparable friends have largely grown apart and moved on with their lives. The movie's heart and soul lies in bringing the two back together in time for Christmas and is part of what makes it so successful. The difficulties of growing up were something that Strauss-Schulson found personally relatable. "There's something true about losing your college friends as you get older and growing apart from each other," he said. "I was thinking about my own personal experience: … having to act like an adult, directing my first movie, but also wanting to be a child and playing with the [waffle] robot. … There's something to me that's personally relatable to it and also to the writers and to John and Kal."

Cho and Penn, of course, have been with the series since the beginning, and despite the characters' separation, the actors' on-screen bond has only strengthened. Their chemistry is infallible; the way they play and bounce off of one another is a constant riot. For newcomer Strauss-Schulson, it was a daunting task to come into the fray with these two veterans. "The franchise is theirs, and I'm the new kid on the block," he said. "I had to prove myself to them. I had a lot of questions for them, they had a lot of questions for me, so that was a pretty rich relationship."

Of course the third essential ingredient in any Harold and Kumar film is the gloriously entertaining Neil Patrick Harris, who literally makes his entrance in a show-stopping musical number. As in the previous two entries, his scenes in 3D Christmas are the best in the film, and this time the writers have amped up the comedy by tackling the actor's open homosexuality head-on. But the Neil Patrick Harris of the movie is as brash and perverted as ever, and the way the writers clash his Harold and Kumar persona with his real one is unbelievably hilarious.

Harris' musical introduction is Strauss-Schulson's favorite scene in the movie, and rightly so. It was his idea "to stop the movie completely for three minutes and forget about Harold and Kumar and forget that they're looking for a tree and just have Neil sing and dance for you. Those were just sort of directorial ideas that everyone was on board for."

Besides contending with series veterans, Strauss-Schulson had the added challenge of dealing with potentially risqué material, including a baby who, throughout the course of the film, gets high sequentially on weed, cocaine and ecstasy. These sequences are outrageously hysterical and potential trouble for the censors, but Strauss-Schulson maintains that they didn't have any studio interference. "It just was very simply a hard R movie. Nothing had to be cut or censored or anything like that." He adds that ultimately it was the movie's heart that won the censors over. "I think that because the movie is kind of sweet and because that stuff borderlines absurdity … it lets you laugh at it. It's not cynical, it's not mean; it's just crazy."

In the end, it is that combination of sweetness and absurdity, comedy and humanity that really defines Harold and Kumar. For fans of the series, A Very Harold and Kumar 3D Christmas presents a fabulous return to form, and Strauss-Schulson certainly has left his mark on the franchise. One can only hope that Neil Patrick Harris wasn't just teasing the audience when he said, "See you in the fourth one."