Nathan Fillion will be playing Greek god Hermes in the second Percy Jackson movie, Sea of Monsters. Check out what he had to say about the experience!

Nathan Fillion is, of course, well known for playing Mal in the cult TV show Firefly, which was cancelled after only one season, and the follow-up movie, Serenity. At the moment, he plays the title character on Castle. During the show’s hiatus, however, he took time to join the cast in the sequel to Percy Jackson and the Lightning Thief.

Fillion will be playing Hermes, god of messengers, travel, and thieves, among other things. In the books, Hermes is Luke’s father and an ally to Percy and his friends. He helps Percy by giving him a quest and offering several magical items, including a thermos that holds winds from the four corners of the Earth, as seen in the recently released trailer.

Hermes made a cameo in the first movie, played by Dylan Neal, although his role is much more important this time around. In an interview with TV Guide, Fillion talks about his character, saying, “I’m not allowed contact with humans as a god, so I dress as a UPS guy.” In one of the scenes, he takes Percy and his friends to a parcel-sorting facility.

Fillion is an established and well-loved actor. So, what did he have to say about Logan Lerman, Alexandra Daddario, and Brandon T. Jackson? “The three young actors restored my faith in humanity of what Los Angeles actors can be like,” he says. “They were having fun — supercool, prepared and professional. A very comfortable, great place to be!”

There isn’t much higher praise than that!

Don’t forget that Sea of Monsters comes out on August 16. It stars Lerman as Percy, Daddario as Annabeth, Jackson as Grover, and Jake Abel as Luke. Fillion (Hermes), Stanley Tucci (Dionysus), Leven Rambin (Clarisse), and Douglas Smith (Tyson) also star.