Walter Koenig’s favorite Chekov moment comes from Star Trek IV: The Voyage Home, and you can probably guess what it is.

Star Trek‘s Walter Koenig revealed his favorite moment as Pavel Chekov is from Star Trek IV: The Voyage Home. Koenig’s Ensign Chekov joined the cast of Star Trek: The Original Series in the show’s second season as the young navigator on the USS Enterprise, under the command of Captain James T. Kirk (William Shatner). Over the course of his time on TOS and its subsequent films, Chekov performed numerous duties on the ship, including filling in for Spock (Leonard Nimoy) at the science station on the bridge.

Mr. Chekov was incredibly proud of his Russian heritage and would often claim (incorrectly) that various important inventions came from Russia. Star Trek creator Gene Roddenberry reportedly asked Koenig to emphasize his Russian accent to add an element of comic relief to the series. This decision led to some great moments throughout the series, most notably in Star Trek IV: The Voyage Home. The Leonard Nimoy-directed fourth Star Trek film took a more humorous and universally appealing approach, which turned out to be a great success, as The Voyage Home is generally regarded as one of the best Star Trek films.

Walter Koenig’s Favorite Star Trek Chekov Moment Is “Nuclear Wessels”

Chekov has some hilarious moments in Star Trek IV: The Voyage Home.

Now 87 years old, Walter Koenig continues to make appearances at Star Trek conventions and events, speaking fondly of his time on the Enterprise. On the last day of Star Trek: The Cruise VII, IGN sat down with Koenig for an interview, where he spoke about his favorite Star Trek moment. Read his quote below:

It was not that significant, but it was just such a delight… And that was the improvisation that I did in Star Trek IV [The Voyage Home] when I approached the crowd and asked them where the ‘nuclear wessels’ were. That was just great fun. I loved the opportunity to do comedy anyway, and that was a delightful little moment. It was a moment. It was not more than a moment. But when Leonard [Nimoy, who directed the film] finally yelled, ‘Cut,’ and I looked at his big, broad smile on his face, I felt really good. And I thought that this was great fun.

Every main character from Star Trek: The Original Series has something to do in The Voyage Home, and the film distinguishes itself as Star Trek’s first true comedy film. Humor has always been a part of the Star Trek franchise, and The Voyage Home leans into that in the best way. Between Chekov’s “nuclear wessels” moment and Spock’s attempts to master 20th-century cursing, The Voyage Home has some of Star Trek’s most quotable lines. The cast members of TOS are truly at their funniest and Leonard Nimoy’s direction seems to bring out the best in everybody.

Star Trek IV Was Walter Koenig’s Best Movie As Chekov

Chekov had more to do than in previous Star Trek films.

While Star Trek II: The Wrath of Khan had some strong moments for Chekov as well, Star Trek IV: The Voyage Home gave the character more to do and made him more central to the plot. The Voyage Home follows Kirk and his Enterprise crew as they travel back in time to 1986 San Franciso in order to save the future. The story involves finding a couple of humpback whales and taking them back to the future so that their whale song can be used to divert a dangerous probe. Star Trek IV’s plot is ultimately secondary to the fun of watching Kirk and his friends navigate the 20th century.

Kirk and his friends soon split up to accomplish their objective, and Chekov and Lt. Nyota Uhura (Nichelle Nichols) are sent to find a nuclear reactor that will be necessary to power their ship for the journey home. As Chekov begins asking people where the “nuclear wessels” are, a real-life San Francisco police officer eyes him suspiciously, unaware of the movie being filmed. In the end, Kirk and his crew save the Earth and set off for more adventures on the newly christened USS Enterprise-A. Walter Koenig will always be a beloved member of the Star Trek family, and his “nuclear wessels” moment remains as iconic and memorable as ever.