The BBC has released a five-minute prequel episode for Blue Planet 2, teasing what's in store when Sir David Attenborough's beloved nature documentary returns for a second series later in 2017.
The video also features Attenborough's narration and a collaboration between Radiohead and Hollywood composer Hans Zimmer, who worked together on a new version of the legendary band's 2011 track Bloom, entitled (ocean) Bloom.
The extended trailer (embedded below) shows off sequences from the upcoming series as well as exclusive footage that won't make it into the final show.
We see dolphins spitting water to trick their prey, otters swimming through vast seaweed forests, coral reefs bustling with life and the dark depths of the oceans' deepest trenches.
Blue Planet's first series debuted in 2001, and remains one of Attenborough's most famous projects.
When the collaboration between Radiohead and Zimmer was announced in September, frontman Thom Yorke said in a statement: "Bloom was inspired by the original Blue Planet series so it's great to be able to come full circle with the song and re-imagine it for this incredible landmark's sequel.
"Hans is a prodigious composer who effortlessly straddles several musical genres, so it was liberating for us all to work with such a talent and see how he wove the sound of the series and Bloom together."
Zimmer, known for composing film soundtracks including those for The Dark Knight and Inception, said: "Bloom appears to have been written ahead of its time as it beautifully reflects the jaw-dropping lifeforms and seascapes viewers are introduced to in Blue Planet 2.
"Working with Thom, Jonny [Greenwood] and the boys has been a wonderful diversion and it's given me an interesting peek into their musical world. They've been incredible to work with and I hope everyone likes the track."
The new arrangement of Bloom was recorded, along with new vocals from Yorke, at London's AIR studios with the BBC Concert Orchestra.