The Moclan delegation arrives on Krill. The Moclan Ambassador offers an alliance to defend against the imminent Kaylon attack.

Teleya says the Krill believe the planets in the most danger are Vikarris and Xelayah.

The Moclans offer armaments in exchange for the protection of the Krill fleet.

The Moclans insist they will lead the combined military since Teleyah is female.

Teleyah insists command be shared. The ambassador states he’ll need to consult his government.

The Union fleet encounters an overwhelming number of Kaylon ships at Xelayah. Surrounded, Burke in Engineering reports on the arming of a device. Once it is armed, Mercer orders Isaac to initiate. The device puts out a pulse that destroys the Kaylon vessels.

At Union HQ, the Orville crew meet with the Admirals. Isaac and Burke are commended on the development of the weapon which they worked on together.

When asked if the weapon could be used on a larger scale, Isaac and Burke explain that with a great enough power source, the range could be unlimited.

The secret to the weapon is the synchronization matrix the Kaylon use to connect to each other. The device causes a feedback loop in the chain which takes down all Kaylons in the matrix within range.

Isaac is not affected because he is no longer connected to the matrix. Perry orders the next step to be to create a power source that could maximize the device’s range.

Mercer cautions that they are preparing to commit genocide. The admirals do not agree despite the evidence that Kaylons can learn empathy and emotion based on Timmis.

Admiral Halsey agrees there is an ethical dilemma to be considered but the use of the weapon will be up to the Union Council.

In the mess hall, LaMarr and Keyali debate Burke and Malloy on whether or not to exterminate the Kaylons.

The Union Council decides to use the weapon as a deterrent. The fleet will take the device to Kaylon to demonstrate its ability and their willingness to use it unless the Kaylons agree to an immediate cease-fire. If they do not agree, they are authorized to use it to make the point clear.

As the Orville approaches Kaylon, Kaylon vessels move to intercept. The device is prepped and ready.

They hail the vessels with a message of peace. When the Kaylons power up weapons, Halsey warns them they have the weapon they used at Xelayah. The Kaylons fire, Mercer orders the weapon to initiate and the vessels are destroyed.

The next fleet of Kaylon defense vessels fires on them, and they initiate the weapon again, destroying them.

They continue towards the planet and encounter another fleet that does not fire on them. Kaylon Primary hails them and sends them landing coordinates, offering to receive them.

They meet and the Union explains they want the Kaylons to cease all aggressions. The Kaylon ask if the Union plans to enslave them. Mercer points out that they could’ve destroyed them all but didn’t because they aren’t monsters.

The Kaylon realize they have no defense against the weapon and so they will agree to the ceasefire. They insist that they will figure out a way to defeat the weapon.

Topa and the Finn brothers play outside a cabin. Inside, Malloy and Burke sing a duet, Simon and Garfunkel’s “Flowers Never Bend With the Rainfall,” for the crew.

When they finish, Mercer commends the crew on what they’ve accomplished.

Grayson pulls out an old bottle of rum her dad gave her to drink on a special occasion. She feels this qualifies.

Keyali compliments Grayson on the cabin that she inherited from her father.

Klyden and Bortus argue over how to crack walnuts. Keyali comes over a cracks one with her bare hand for him.

Dr. Finn, Isaac, the boys, and Topa admire the Northern Lights.

Burke tells Mercer they should’ve used the weapon and wiped out the Kaylon.

At Union Central, a lieutenant travels to sublevel 32 and tells the personnel there he is to transport the device to a new site. When they try to confirm this, he attacks. One of the other officers in the room backs him up.

The two of them access the device. Referring to themselves as Team Echo, they contact someone and communicate their success. Their message is acknowledged. Their shuttle takes off and goes to quantum.

At the cabin, Grayson and Finn watch the sunrise.

The comm beeps. Halsey informs her the team is needed as the device has been taken.

The shuttle docks with a Krill vessel. A Moclan one waits adjacent. Aboard the ship, Teleya admonishes Admiral Perry for being late. His purpose for handing the weapon over to them is for them to use it on the Kaylon. He believes as Burke does, that the tactical advantage will be lost if they give the Kaylon time to find a defense against the weapon.

Perry lets them know only Burke and Isaac know how to use the device. The Moclan-Krill allied scientists will have to figure it out on their own.

Perry leaves them to return to Earth and turn himself in. As his shuttle leaves, Teleya has his shuttle destroyed to prevent him from informing the Union of the Moclan alliance.

On Earth, Halsey figures out it was Perry and the Orville follows the shuttle’s projected coordinates towards Krill space.

They find the shuttle debris and detect Krill and Moclan weapon signatures and realize Perry’s intention. When they puzzle out how they plan to figure out the weapon, Bortus shares the name of a Moclan weapons expert of great renown, Dr. Kalba, who works on Draconis 427.

When they arrive on Draconis 427, Bortus detects a large quantum core power source at the facility. It is the largest he’s ever seen. Mercer decides they’ll need help.

They let the Kaylon know what has happened and propose an alliance. Seeing no alternative, the Kaylon reluctantly agree.

The Kaylon contingent come aboard the Orville and the strategy to retrieve the device is discussed.

Kaylon Primary intends to join the retrieval team which no one is comfortable with.

The Union fleet engages the Krill ships in orbit around Draconis 427.

The retrieval team prepares to launch.

The Kaylon fleet arrives as a distraction.

LaMarr and Malloy lead the shuttle in a squadron of Pteradons.

The retrieval team jumps from the shuttle with egress packs to avoid crashing while in it.

The team lands and enters the facility. They encounter a group of guards and Grayson sends Burke, Kaylon Primary, and Isaac around the long way while she and Keyali hold off the guards.

At the quantum core, Dr. Kalba informs Teleya the weapon will be ready in eight minutes.

The breach is reported and Teleya orders defensive tactics. Dr. Kalba brings the transmitter array online. Bortus detects this aboard the Orville and Mercer directs Malloy to try to damage the array.

Teleya ambushes Grayson and orders her to order the team to stand down. They fight.

The squadron is unable to damage the transmitter array.

Dr. Kalba initiates the countdown. Kaylon Primary leads the team into the core chamber and orders Kalba to stop the countdown. He informs them that’s impossible. Burke and Isaac go to work breaking the encryptions to shut down the core.

Keyali knocks Teleya out before she can kill Grayson.

Keyali and Grayson bring Teleya to the chamber. Burke informs them the only chance they have is to trigger an overload. She tells Grayson she needs to go before it happens.

Isaac and Kaylon Primary leave too. Kaylon Primary pauses to consider Burke before leaving.

The team contacts the Orville and tells them to tell the fleet to get away from the planet.

Aboard the Orville, Kaylon Primary asks for an explanation for Burke’s actions. Isaac explains the biologicals of the Union are not like the Builders. Kaylon Primary allows that they may have been incorrect in their assessment of the Union biologicals.

Mercer visits Teleya in the brig. He tells her that she is being taken back to Earth to face a trial for attempting to commit genocide. He wants to bring Anaya to live with him. She offers to arrange it if he releases her. She promises that as long as she is a prisoner, he will never have access to Anaya.

On Earth, President Alcuzan offers the Kaylons a provisional seat on the Union Council with the possibility of full membership one day. The Kaylon accept the terms presented.

The Orville pays tribute to Burke. Mercer makes the eulogy. Isaac speaks at the memorial.