A doctoral candidate in marine biology gets more than she bargained for in the deep Atlantic in a new trailer for “Sea Fever.” “I identify and extrapolate patterns from variations in deep sea behavior,” Siobhán (Hermione Corfield, “Rust Creek”) tells the crew of the fishing trawler she’s traveling with. She’ll be photographing their catches for a week.

Siobhán’s fieldwork takes an unexpected — and potentially deadly — turn when a mysterious specimen ensnares the boat and begins to infect crew members.

Though Siobhán warns that these things spread “really fast” and the crew needs to quarantine themselves, everyone else remains determined to make port.

“Sea Fever” marks Neasa Hardiman’s feature directorial debut. She’s helmed episodes of “Jessica Jones” and “Happy Valley,” among other series.

Fantastic Fest is presenting nationwide sneak peaks of “Sea Fever” April 7 at participating Alamo Drafthouse locations. You can catch the pic in theaters and on digital April 10. Hardiman penned its script.