A Scarborough family has been reunited with their pup after he decided to hop on the GO train and take a trip downtown.

Dorte Petersen said she had gone for a walk with her dog Marley on a Scarborough path they’re both familiar with on Sunday. She said they had only been home a short time when she got a strange call from a conductor on a GO train.

“They said, ‘We have your dog and not to worry. The good news is he’s safe and we’re giving him treats but he’s actually headed to Union (Station). He’s missed the boat for getting off at Rouge,’” Petersen told CTV News Toronto.

Somehow the six-year-old Border Collie-Shepherd mix escaped from their home, trotted over to Rouge Hill GO Station and walked onto a westbound train on the Lakeshore East Line.

Marley is no stranger to the station, Petersen said, as they use it regularly to get around.

After weeks of being in a wheelchair, Peterson recently graduated to crutches following knee surgery in May. The pair have often used the elevator at the station while she recovers.

“I think when he got outside he went looking for me and that’s what brought him to the GO,” she said.

After a nearly two-hour journey, GO Transit employees returned Marley to his family.

In the social media post, Kia Andersen, Petersen’s daughter, thanked staff for looking after Marley and getting him back to the family safely.

"Thankfully his cute face made him tons of friends on the train and at Union," she wrote.

Metrolinx spokesperson Anne Marie Aikins said it seems Marley misunderstood GO Transit’s new policy that allows leashed dogs on board trains.

“You’re supposed to have your human with you!! We didn’t charge him for not having his PRESTO card either,” Aikins wrote.

“We are still investibatinbg whether Marley tapped his PRESTO card,” she later wrote in a tweet. “He needs to come back in for questioning but we won’t be too ruff.”

Aikins added that it is “a first” for the transit service’s lost and found department.

Meanwhile, Petersen is still trying to figure out how the pup got out in the first place.

“Only Marley knows,” she said.