King in Black: Namor (2020) #2

The Young Namor, Attuma and Dorma get to accompany the Swift Riders on a mission, see them in action and learn from them. But the mission involves Russian alchemists in 1930s Murmansk, a dangerous mystic relic, and a catastrophe that brings to life the most menacing threat that Atlantis has ever faced! Now all of undersea civilization is imperiled, and only three youngsters can save it!