“Time’s Orphan” is episode twenty-four of season six of Star Trek: Deep Space Nine.
O’Brien and Keiko are in bed when Molly rushes in and tells them to get up since today is the day of their picnic. Keiko and the kids have been away from the station for a while because it wasn’t safe. The picnic is on Bajoran colony and they are all having a good family time together with Molly talking about what she’s going to be when she grows up. Miles promises that they will never be apart again. Which was probably a mistake.
Next, they hear Molly screaming. It’s coming from inside a cave which O’Brien enters. She’s hanging from a ledge above a strange glowing pool of something. Molly slips from O’Brien’s grasp, and falls into the pool. Only she doesn’t exactly – she disappears in mid air.
The crew come down from the station to help. According to Dax, the pool is some sort of time portal and she thinks it’s sent Molly 300 years into the past. The portal is one that has been constructed, but they don’t know how the technology works and Molly falling through it seems to have caused problems. Even when they get it working, getting Molly back may not be easy.
Odo has contacted the Bajorans regarding archaeological records and it seems that the portal was built by a civilisation that disappeared two thousand years ago. The Bajoran colonists have been there less than a century. So Molly is currently alone on a planet that won’t be inhabited again for a couple of hundred years. O’Brien plans to bring Molly back only a few hours at most after she fell into the portal.
They do manage to reactivate the portal, lock onto Molly’s DNA and bring her back using the transporter. Only it wasn’t a few hours after she went. Molly is now about a decade older and has been living alone for long enough that she’s gone rather wild. Even surviving is quite impressive.
O’Brien suggests sending her back and trying again for the eight year old Molly. Julian points out that, if they do that, they will be erasing this Molly from history, and Keiko says that this is their Molly, even if they missed out the last ten years of her life. Reacclimatising Molly to humanity is not going to be easy. O’Brien and Keiko will need to spend time with Molly in a cargo bay that has been converted into what appears to be a planetary environment. And Molly has now been away from them – and all people – for longer than she was with them. The situation proves very difficult.
With O’Brien and Keiko trying to help Molly, Dax volunteers to care for Kirayoshi for quite a bit of the time. Which results in Worf trying to help. Worf is not a baby person. Worf will not back down from the challenge though.