Official WB Description Dean and Sam investigate a series of mysterious drownings written off as suicides. They discover the spirit is an angry little boy with the power to travel through water who is taking revenge on certain town inhabitants for a dark secret buried long ago. Dean forms a bond with a young boy who seems to have the power of premonition.
| November 2005 (day 1) | Sophie Carlton drowns |
| November 2005 (day 5) | Sophie Carlton's funeral |
| November 2005 (day 7) | Dean and Sam arrive in Lake Manitoc, WI; interview Will Carlton, Sheriff, Andrea, Lucas; Will Carlton drowns |
| November 2005 (day 8) | Dean and Sam speak to Bill Carlton; reinterview Lucas; find and speak to Mrs. Sweeney about Peter; Bill Carlton drowns; Sheriff tries to run Dean and Sam out of town; Dean and Sam save Andrea from drowning |
| November 2005 (day 9) | Reinterview Andrea; find Peter's bike; Dean saves Lucas from drowning; Sheriff Jake Devins drowns; Peter Sweeney's spirit is put to rest |
| November 2005 (day 10) | Dean and Sam say goodbye to Andrea and Lucas |
Dean and Sam decided to investigate the drowning of 18-year-old Sophie Carlton, as she was the third drowning victim in the last year whose body has not been recovered from Lake Manitoc. They posed as federal wildlife officers and spoke to the local sheriff, Jake Devins, who told them that they found nothing in the lake despite running a sonar sweep, but that the lake will soon drain away because the local dam was leaking. While they are at the sheriff's office, they also met Jake's daughter, Andrea, and her son, Lucas. When Dean and Sam researched the lake further, they learn that not only have six other people disappeared in Lake Manitoc over the last 35 years, but also that Lucas witnessed his father's drowning earlier that year.
That same night, Will Carlton drowned in the kitchen sink when something dragged his head below the surface of the water. Sam informed Dean of Will's death, and they conclude that whatever was in the lake knows the lake was draining and that it was running out of time to get its revenge. They also assumed that Sophie and Will's father, Bill Carlton, was somehow involved, as the thing in the lake had targeted his children and his godson (Lucas' father). They do not learn anything from Bill when they go to speak with him, but Dean noticed that the drawing Lucas gave him earlier was of the Carltons' house.
The brothers visited Lucas again, and Dean told him about his own experience of losing his mother. Lucas provided Dean with a second drawing depicting a house next to a white church and a boy wearing a cap with a red bicycle. Dean and Sam find the church and the neighboring house, and they visited the woman who lived there. They discovered that her son, Peter Sweeney, vanished 35 years ago with his red bicycle. Dean spotted a photo of Peter with Bill Carlton, and the brothers think that Bill may have killed Peter and the thing in the lake was Peter's vengeful spirit. They went back to talk to Bill, but they were too late as they witnessed Bill make his way to the middle of the lake in his boat. The boat flipped over, and Bill vanished under the water.
After the incident with Bill, the sheriff tried to run Dean and Sam out of town because he discovered that they were not really federal wildlife officers, but they snuck back because Dean suspected that the hunt was not over. They arrived at Andrea Barr's house just as she was dragged under the water in her bathtub. After Sam pulled her out of the water, she told him that she heard a voice in the water that said, "Come play with me". Meanwhile, Dean went through Andrea's photo albums and discovered an old photo of Andrea's dad, Jake, with Peter. Dean assumed that Jake was probably also involved in Peter's death, and that Peter's spirit was targeting Bill and Jake's loved ones.
Lucas leads them to a spot near the lake where Dean and Sam dug until they discover Peter's bicycle. Jake appeared and held the brothers at gunpoint. He revealed that he and Bill buried the bike after they accidentally drowned Peter and let his body sink in the lake. Suddenly, Lucas was pulled into the lake by a ghostly hand. Dean and Sam dove in after him with no result until Jake walked into the lake and called for Peter to take him instead of his grandson. Peter dragged him under the water, and Dean is able to save Lucas.
Dean and Sam prepared to leave and Andrea and Lucas see them off. Lucas had begun to talk again, and Andrea thanked them both for saving Lucas. As a parting gift, Dean taught Lucas the phrase "Zepplin Rules!"
"...but Dead in the Water holds a special place in my heart, too. I liked what my character had to go through in that episode. It was kind of the first time where I really got a sense of who Dean was, and I was able to peel back some layers. I thought it was a good story that was directed well, so that was definitely one of my favorites. When I had to hold my breath with that kid, holding him in my arms...I hope you've never had to experience something like that. When you're treading water, just getting your mind around having two people below you in the water, pulling you down...that was a really weird sensation that I wasn't prepared for, not to mention I was responsible for the life of this 10-year-old kid that was in my arms. He's supposed to be dead, so he's limp. I'm actually treading water, keeping us boat afloat with my left arm. And when they say action and I have to hold my breath, he holds his breath, and I have two divers pulling me down. So after the first time, I kicked the divers loose and I sprung right back out of the water and I'm like, 'Okay, wait a second - I'm going to need a minute for this one.' But we ended up getting the shot, and it was nice."