|“|| Alyssa, it'll be okay. I'm here. I'll do anything to help you... Don't forget, you can count on me. If there's anything I can do, just ask.
Dennis Owen (デニス・オーヴェン Denisu Ōwen) is the deuteragonist of Clock Tower 3. He is a fellow student whom Alyssa Hamilton attended primary school with; he has a crush on Alyssa and is persistent on staying as close to her as possible. He is a good friend and tries his best to help her, appearing out of nowhere three years after primary school to meet Alyssa in her house, only to find her in grave danger. His older sister who raised him, Linda Owen, is a nurse in Africa.
Clock Tower 3
Dennis knocks on Alyssa's window, while hanging on to the windowsill. Alyssa helps him up, in anger, wondering why he would try to enter her residence, and Dennis gives the key to her grandfather's room to Alyssa. Dennis searches the upstairs floor, until the Hamilton House transforms into the Clock Tower.
After Alyssa defeats Chopper and frees the Rooders, The Dark Gentleman appears and kidnaps Nancy Hamilton. Dennis comforts Alyssa, and the two find themselves in a forest by a city. While exploring the city, Linda appears in a hospital window and calls out for Dennis. Dennis enters the hospital, only to discover Scissorwoman Jemima was posing as her. Dennis is then kidnapped by the Scissor Twins.
While in Burroughs Castle, Alyssa finds the Scissor Twins torturing Dennis with a giant pendulum. Alyssa defeats the Scissor Twins and saves Dennis. The Dark Gentleman tells Alyssa that in order to save her mother, she must challenge him at the top of the Clock Tower. Alyssa orders Dennis to stay behind, as he's not a Rooder and it's too dangerous.
Dennis disobeys Alyssa and climbs to the top of the tower, only to discover Alyssa about to be sacrificed. Dennis finds the last piece of the clover pendant which fell from Nancy's crushed remains, and tosses it to Alyssa. Alyssa unleashes her Rooder powers and Dennis attempts to pin down Darcy Burroughs, but is knocked off the clock tower. Alyssa defeats Darcy Burroughs and the clock tower crumbles. Alyssa wakes up in a clover field and discovers that Dennis is still alive, and the two embrace with a hug.
- There is a notable fan theory that Alyssa and Dennis are actually dead in the ending and that the clover field is actually some sort of afterlife, or that they may be ghosts, or the entire clover field scene is Alyssa's dying hallucination. Dennis inexplicably "survives" from falling off the top of the castle, and Alyssa somehow "survives" the crumbling of the castle. The ultimate fates of Alyssa and Dennis are never mentioned anywhere else.
- Dennis is the same exact height as Alyssa.
- Dennis' hair is similar to Lotte's hair meaning that both Alyssa and Jennifer Simpson have redheads as their best friends.
- Dennis bears a strong resemblance to Ron Weasley from the Harry Potter series. In addition, Alyssa bears some resemblance to Hermione Granger, Ron's love interest.