1x02: "Haunting Memories"
Not trusting Dark after his powers to cloud memories are revealed, Miranda turns her investigative skills on Dark's past. She is not altogether pleased with what she finds. Meanwhile, Dark struggles with cash-flow, and some of his past crops up and starts haunting him -- literally.
Years ago, Dark was present in a chatroom where one of the regulars died. He has second-guessed himself for not calling emergency services ever since. As he was directly connected to download a directory from the dead man, he could have cracked into other files on his computer, found out his location, and called emergency services right away and maybe been in time. (After they realized he'd been idle too long, the connection had closed, and they had to find things out less elegantly, and the medics were too late -- it may have been too late by the time they realized he'd been idle.) Now his unquiet spirit has returned and is haunting Dark. Desperate, Dark turns to Miranda, who is able to find and publish the required information, but not without some very sharp words to Dark. Finally, the ghost is put to rest.