There are two worlds. The one we know, & the one below. Aspen Matthews was a marine biologist who, in a failed experiment, discovered that she is actually a water nymph, able to live and thrive beneath the water.
Aspen Matthews from Fathom.
Fathom is on sale until 6/5, including a bundle that gets you both Fathom Omnibuses, available only on comiXology.com!