The USS Enterprise-D is on its way to Sarona VIII for shore leave. Captain Jean-Luc Picard is getting a head start by fencing with Lieutenant Dean. Although he loses the first point, he wins the second. As Dean congratulates him, time loops, and the moment is repeated.
Picard hails Riker, who confirms that it also occurred on the bridge. The captain joins them there, and Data reports that, although sensors don’t show anything, a moment in time repeated itself, for everyone. Worf then receives an automated distress call from the Pegos Minor system from Paul Manheim, calling for help and directing them to a set of coordinates.
Picard remembers that Manheim left Earth fifteen years previously, along with a team of scientists, to perform experiments on non-linear time. It must be related, and he orders the helm to travel there immediately at warp 8.
Data explains that Manheim was highly respected, particularly because of his theories about the relationship of time and gravity, but his theories didn’t find acceptance.
Picard says that he knew of Manheim teaching at the university in Paris when Picard was there, but never met him. After he orders Riker to check how widespread the time distortion was, Deanna Troi approaches him. She tells him Manheim’s name caused an emotional response in him, and advises him to try to analyze his feelings in this area. Picard brushes off her concerns and leaves the bridge.
Picard goes to the holodeck, where he recreates the Café des Artistes, Paris, 22 years previously on April 9th, “a warm spring day“, as he recalls it. He enters and is greeted by the waiter. He admires the view, and tells the waiter he had a rendezvous with a woman there many years before, and he didn’t show. He sits at a table, and overhears a conversation between two women. One of them, Gabrielle, is waiting for a man to show up. The other gets frustrated and leaves. Gabrielle asks Picard why her man didn’t show. He answers that maybe he was afraid, but then gets annoyed with himself, declares “enough of this self-indulgence” and leaves for the holodeck.
Picard arrives on the bridge and Riker tells him that the USS Lalo and the farming colony on Coltar IV both experienced the loop. Since Manheim was performing time-gravity experiments, it could be linked to him.
The Enterprise reaches the given coordinates, but there is nothing there. Then new coordinates arrive, directing them to the Vandor system, a binary system of a red giant and a pulsar. When they reach Vandor, Data detects activity on Vandor IV, a planetoid in an elliptical orbit of the binary system. On it, Worf detects a small force field.
Picard hails the planet, but doesn’t mention his name. A woman answers, saying Manheim is having convulsions. She lowers the force field, and both are beamed directly to sickbay. Picard heads there with Data and Riker.
Picard introduces the woman as Jenice Manheim, and asks her what happened. She says a second lab was completely destroyed in an accident, killing everyone but her and her husband. Manheim believed that there were infinite dimensions, and that by changing the constancy of time, a window could be opened to these dimensions as, according to him, time is no more immutable than space is.
Jenice goes on and says his husband’s team spent two years searching for a location before settling on Vandor, a planetoid in a system with the pulsar’s dense gravity, and that he thought he was very close to proving his theories. And then the accident happened.
Jenice says Manheim might have considered the experiments dangerous, as he had installed a security system and force fields, and he made her stay in a protected room whenever he performed an experiment. As he neared his goal, he became more and more obsessive, maybe causing his judgment to be clouded.
She also tells Picard he’s done well, being the captain of a great starship, just has he hoped. Picard chuckles and responds that nothing works “just as you hoped”. Then Dr. Crusher enters and asks to do some tests on Jenice, who kisses Picard on the cheek as she leaves. Crusher tells Picard that Manheim is dying, but she doesn’t know why.
The three officers leave sickbay and enter a turbolift, for the bridge, but when the doors open they see themselves in the corridor before they got on the lift. As the doors close, the “past” Data supposes that the Manheim Effect is becoming more pronounced, before they enter the lift.
In the captain’s ready room, Data says there is immense energy emanating from the planetoid’s core being focused at the lab : it seems like Manheim as developed a method for harnessing energy from the pulsar. Riker says if they want to find out what’s going on, they’re going to have to beam down, and Picard agrees. The away team tries to beam down, but they can’t materialize on the planet, as the signal is being bounced back up. Transporter chief Herbert (hello !) is afraid he is losing them.
Fortunately, Herbert is able to bring all three back to the Enterprise, and Riker contemplates options.
In sickbay, Manheim wakes. He tells Jenice that it was all worth it, and that he has been on the other side, another dimension. His mind is still floating between two places. Picard and Data arrive, and the captain asks Manheim to explain the situation to Data.
Manheim tells them he was able to harness a dynamic energy source in the center of the planetoid and open a crack, a window to another dimension, but when he learns how far the effect has spread, he tells them it must be shut down. He will give them the transporter coordinates and the security codes, so they can get into his lab to get his notes.
In the observation lounge, Data says the closing of the window must be timed to match the occurrence of the effect, or the new dimension will rip further into the fabric of the galaxy and reality itself will be fundamentally changed and become unrecognizable.
Jenice comes in as they are leaving, and Picard remains behind to talk to her. She asks him why he didn’t come. They joke about it, but he eventually tells her he was afraid of staying, of losing himself. She says the real reason was that he thought life with her would be ordinary.
Troi visits sickbay. She asks Crusher how Manheim is doing, but she really wants to talk about how Beverly feels. The doctor says she can’t compete with a ghost from the past, which is what Picard sees when he sees Jenice.
On the bridge, Data informs Picard that the next distortion will occur in 28 to 47 minutes. Picard then is called down to sickbay to talk to Manheim who wants to speak with him, alone. He warns Picard he might have forgotten some of the security codes, and ask for anyone going down there to be cautious. Then, he asks Picard to take care of Jenice if anything should go wrong. Picard agrees, and Manheim tells him she has had a terrible time the last few years. He gave her no attention, and he thinks she deserves better. Picard suggests he underestimates her, as he had done.
Picard tells Data he wants him to go down alone. Data thinks that’s because he is a machine and he is expandable, but Picard explains that since he is not affected as badly by the time distortion as the others, going alone will decrease the risk of disorientation affecting the mission. Data agrees, and he beams down successfully. As he approaches the lab, he is fired on by phasers mounted on the wall, but manages to destroy them. He keeps an open comm channel as he goes into the lab.
Data enters the lab and finds a console. He determines that the next distortion will occur in ninety seconds. Data explains he has to add antimatter to realign the system, at the appropriate moment. He then asks Geordi for a 27 seconds countdown.
Data gets the antimatter and goes to the opening. Suddenly, there are three Datas, only one of whom is in the correct time continuum. He/they figure out which one it is and they/he releases the antimatter and seals the hole. He then reports that it is “well patched”, as he cannot guarantee it is permanently closed.
Meanwhile, in sickbay, Manheim has returned to normal, but is unable to describe his experiences, only saying there is some kind of life on the other side. As his lab is intact, he wants to go back and finish his experiments, telling Jenice he has learned too much to give up, and that he owes it to his friends.
Later, Troi brings Jenice to the holodeck, where Picard awaits in the Paris program. He tells her he wanted to say goodbye properly. She thanks him for Paris and Picard returns to the bridge, where he orders Geordi La Forge to set course for Sarona.