The story introduces Dory as a "baby blue tank fish" who lived with her parents, Jenny and Charlie. Dory was distinct from other fish because she "suffered from short-term memory loss." To help her navigate, her parents "collected shells and made trails" for her, a gesture of love designed to ensure she could "find her way home." However, tragedy struck when Dory, distracted by a "pretty purple shell," wandered too far and was "pulled away by the undertow," leaving her alone and unable to remember her origins.
After losing her way, Dory eventually "crashed into Marlon," who was searching for his son, Nemo. Through their partnership, Dory helped Marlin find Nemo, and she subsequently "went to live with them in the coral reef," finally finding a sense of belonging. Her life took a turn during a school field trip to see the "stingray migration," where Dory was once again "pulled into the undertow." This traumatic event acted as a catalyst, as she was suddenly "flooded with memories of her mom and dad," sparking a desperate desire to return to her roots.
With the support of Marlin and Nemo, Dory traveled to "Morrow Bay," eventually finding herself in the "Marine Life Institute." Here, she met Hank, a "cranky septipus" with "three hearts" who agreed to assist her. Her journey was further aided by reconnecting with "pipe pals" from her past, specifically Destiny, a whale shark who was shocked to hear Dory "speaking whale," and Bailey, a beluga whale. These friendships were crucial in guiding Dory toward the "open ocean exhibit."
As Dory navigated the institute, she relied on her friends to move through the facility, with Hank helping her "rolled, swam and swung" across the institute. Despite the emotional difficulty of saying goodbye to Hank—who jokingly remarked, "You'll forget me in a heartbeat, three heartbeats"—Dory pressed on.
Upon reaching her old home, she initially found it "empty," but the sight of a "purple shell" triggered her core memories. She remembered her "mom and dad hugging her." Following the advice of a crab, she navigated the pipes and returned to the ocean. In a moment of triumph, Dory spotted a trail of shells. By following this "trail of shells," she finally reunited with her parents. The story concludes with Dory "home again, surrounded by her family and all of her friends," proving that even with short-term memory loss, the bonds of love are never truly forgotten.