Plot summary
Transporter Chief Miles O'Brien (Colm Meaney) and civilian botanist Keiko Ishikawa (Rosalind Chao) are about to be married, and Data (Brent Spiner) has been asked to give the bride away. After Keiko calls off the wedding, Data seeks advice from Geordi (LeVar Burton) and Counselor Troi (Marina Sirtis). He attempts to convince Keiko to go through with the wedding. To prepare, Data asks Dr. Crusher (Gates McFadden) to teach him how to dance. She instructs him in tap dance and ballroom dancing.
Meanwhile, the Enterprise is taking Vulcan ambassador T'Pel (Sierra Pecheur) to a secret meeting with a Romulan ship inside the neutral zone. T'Pel asks Data about the Enterprise 's defense capabilities, but claims she was merely testing Data's security safeguards. During the Enterprise rendezvous with a Romulan warbird, the Devoras, T'Pel is seemingly killed during a transporter accident. Picard and the Romulan captain agree to both leave the Neutral Zone.
However, Data deduces that T'Pel was not really killed, and that the Romulans beamed her away and staged the accident. Picard returns to the Neutral Zone and intercepts the Romulans. He learns that T'Pel is actually a Romulan spy using the Enterprise to return to the Romulans. Multiple Romulan vessels enter the neutral zone and Picard retreats into Federation space.
Keiko agrees to proceed with the wedding. She and Miles are married by Captain Picard. Data notes that he understands the emotions of love and belonging.
Credits
Adapted from Wikipedia contributors, Data's Day. Paragraphs and formatting adjusted; illustrations, reference markers, block quotations and non-story material omitted.