In the now, the Discovery stops its journey to Vulcan when it receives a distress signal from the U.S.S. Enterprise.
In the past, Michael as a grieving orphan is brought to Amanda and Spock by Sarek. Spock is not welcoming.
With communications compromised, Tilly suggests Morse Code. Pike requests permission to come aboard with two officers. Burnham and Sarek expect that Spock will be the science officer.
Saru senses Burnham's excitement and Burnham's dismisses it as mission-readiness.
Pike's party arrives and Spock is not with them. Pike takes command of the Discovery and explains that they are investigating seven bursts of energy simultaneously detected. Only one is still emitting.
They set course and, under Pike's command, begin the new mission.
Stamets is re-watching old video correspondence from Culber and a little distracted from Engineering tasks. Tilly is explaining where she's assigned Stamets but he tells her to put everything into storage because he's going to take a position at the Vulcan Science Academy. He says he needs to leave because everything reminds him of Culber. Tilly tries to convince him to stay.
Burnham reads "Alice in Wonderland" and relives the first time Amanda read it to her. Spock watches them from a distance.
Sarek visits and they discuss the signals and Spock. He rules out the Klingons being involved in the signals. They discuss how Spock did not welcome Michael and did not learn empathy from her the way Sarek had hoped he would. He plans to leave the ship as soon as they drop out of warp.
When the Discovery drops out of warp, the ship is rocked by an impact. They discover the source of the signal is an asteroid. When they try to approach, they are repulsed away and the asteroid's trajectory changes sending it towards a pulsar where it will be incinerated. Using Discovery's telescopic cameras finds a Federation ship crashed on the asteroid's surface.
Burnham comes up with a plan to search for survivors on the asteroid. On the way to deploy, Tilly grabs her and asks her to bring back a sample of the asteroid. She also tells her that Stamets is leaving.
The away team launches in pods. Connelly won't take advice and gets killed. Pike's pod is damaged but, with a coordinated effort by Discovery's bridge crew, Burnham is able to grab him and bring him safely to the asteroid's surface.
Burnham, Pike, and Nhan reach the wreck of the U.S.S. Hiawatha. They are scanned by a drone and they meet Commander Reno. She doesn't know the war is over. She's kept her crew members alive for ten months through sheer ingenuity.
They begin setting up a system to transport everyone to the Discovery, six at a time. Pike asks Reno about the signal they were tracking but she has no idea what that's about.
On the final transport, the power shorts and Burnham jumps off the transporter pad to fix it. There's an explosion and she gets knocked out of the transporter room. The structure is imploding so she runs for it, asking Discovery to track her signal. Another explosion knocks her out and puts a piece of shrapnel through her leg. Pike returns and orders their transport back to the Discovery. Burnham tries to grab a piece of the asteroid for Tilly but it doesn't transport along with her and Pike.
Tilly finds Burnham in sick bay and, although she doesn't have the sample, she theorizes why the transporter couldn't lock onto it. She sends Tilly to retrieve one of the chunks that has fallen off the asteroid before the pulsar swallows them all up.
Stamets tracks Tilly's activities and is excited by the possibilities of the asteroid. They plan to use a gravity simulator to catch an asteroid piece.
Pike returns the command of Discovery to Saru and he gives the orders to capture the asteroid piece.
Burnham finds Pike in Lorca's ready room, dressed in a Discovery uniform. He has been given command of Discovery again and ordered to investigate the source of the bursts.
Burnham asks Pike if she can go over to the Enterprise to talk to Spock and he informs her that Spock is on leave and is not on the ship.
Pike shares that Spock had changed before he asked for leave. Burnham still wants to go to the Enterprise and look at Spock's quarters. She finds Spock's logs and remembers seeing him for the first time as a child. She discovers that he had mapped the seven bursts before he left the ship, before the bursts had been detected.