A fantastical kingdom. A perilous quest. A young, untested but brave hero. All of this is a bit old hat for Andy Serkis, the erstwhile Gollum from The Lord of the Rings trilogy. But despite a similar medieval-fantasy milieu and even a New Zealand shooting locale, Netflix’s upcoming series The Letter for the King still offered something new for Serkis: acting opposite his daughter, Ruby (Hulu’s National Treasure), for the first time.

The Serkises bring a measure of levity to the series, which follows a would-be knight named Tiuri (Amir Wilson of His Dark Materials) who’s tasked with delivering the titular missive. Andy plays the scheming Mayor of Mistrinaut, a once-mighty trading hub that’s fallen on hard times, while Ruby gets her first major showcase as the Mayor’s equally cunning daughter Lavinia. The characters’ bantering, warm-yet-spiky interplay has an authentic chemistry that reflects the actors’ real-life relationship.

“It’s been a really interesting dynamic because we’re playing versions of ourselves but we’re not ourselves,” the elder Serkis notes in a press release. “Where do we cross over as human beings? Where do we crossover as father and daughter? Obviously these characters are very different, but we’re using a shorthand that we know with each other.”

Image zoom Julie Vrabelová/Netflix

Seeing Serkis’ face untouched by CGI was a bit of a jolt for Wilson, who knows the 55-year-old actor from LOTR and playing “a monkey” in the rebooted Planet of the Apes trilogy. “I’d never actually seen what he looks like,” admits Wilson with a laugh. “It’s quite mental, actually.”

Wilson didn’t spend much time on set with his famous costar, though. The story begins in the city of Dagonaut, where the good-hearted misfit Tiuri strives to become a knight. On the eve of completing his training, he is reluctantly drafted for a journey across warring kingdoms to deliver the fateful letter and save the realm from the murderous, power-hungry Prince Viridian (Dutch actor Gijs Blom). Much like his character, Wilson was venturing into an unfamiliar realm, between the location-heavy shoot and tackling his first leading role.

“It was a lot to take in at first. Reading these scripts, I thought, how am I gonna be able to do this?” Wilson says. “I thought it’d be quite hard for me, ’cause I’m quite new, and quite young, and not as experienced as other people. But I had a great group of people around me to help and support me.”

And despite what the eerie teaser above might suggest, don’t expect the gory, hard-R escapades of Game of Thrones; Letter is a family-friendly affair. “You can enjoy the adventure without a lot of violence,” assures Wilson.

The Letter for the King debuts March 20 on Netflix. Check out more first-look images below, and the exclusive teaser up top.

Image zoom Julie Vrabelová/Netflix

Image zoom Julie Vrabelová/Netflix

Image zoom Julie Vrabelová/Netflix