In the next episode of "The Orville," Ed Mercer (Seth MacFarlane) and Gordon Malloy (Scott Grimes) go on an undercover mission disguised as the Krill.

The trailer for the upcoming installment titled "Krill," showed Mercer and Malloy in their space vessel turning on their holographic disguises as the adversarial Krill creatures. However, before they go on their dangerous journey to destroy the enemy ship, Mercer's second-in-command and ex-wife Kelly Grayson (Adrianne Palicki) tells him to be careful as Lt. Cmdr. Bortus (Peter Macon) and Lt. Alara Kitan (Halston Sage) look on with concern.

Mercer and Malloy soon are on the enemy's alien vessel and find out there are Krill women and children on it. "If we destroy this ship...the children onboard, we have no souls," Mercer tells Malloy with conviction. The Krill are a sworn enemy race who has attacked the U.S.S. Orville in the past. It seems that Mercer will come to a fork in the road and has to decide on whether to destroy the ship or leave it untouched but risk future attacks with the Orville.

In the last episode, Mercer and his crew encountered danger when they let on board Pria Lavesque, a supposed Lieutenant of the Planetary Union. It turned out that she was a shady time-travelling businesswoman from the 29^th century who wanted to bring the Orville to her future and sell it to an alien entrepreneur.

Lavesque had control of the ship and brought it back to the 29^th century. However, the ship's robot Isaac (Mark Jackson) was able to get into its system and regain control and go back to the previous time. They captured Lavesque and destroyed the space wormhole that connected to the future timeline.

The next episode of "The Orville" will air on Thursday, Oct. 12 at 9 p.m. EDT on Fox.