Mark Waid and Minck Oosterveer's four-issue mini about a terminally ill detective trying to solve the mystery of what happens after we die before she dies concludes with a lot of action and suspense. "The Unknown" has been a series that mixes a lot of elements well and this final issue is no exception; Catherine and James are finally staring death in the eyes thanks to a doorway in the basement of an asylum.

The revelation of what happens behind the supposed doorway to the afterlife is chilling, as both Catherine and James encounter things that shouldn't be there. Catherine's quest to solve her mystery even puts both in even greater harm thanks to the pale-skinned, grinning specter of death that's shown up throughout the series, but James continues to be the rock of common sense. Though, even he has difficulty coping with what they discover.

While most of the issue is a great read, this finale lacks a strong conclusion to the search for what awaits us after death. That's purposeful on Waid's part and part of the thematic wrap-up of the story, maintaining the larger mystery and renewing Catherine's zeal for solving the mystery, but it's also a little bit of a let down. Of course Waid doesn't know anything more about what lies beyond, but something more would be nice. It's difficult to maintain that balance between creating a satisfying conclusion and leaving things open, and I'm not sure he pulls it off.

The climactic scene past the doorway, as well, happens too quickly and too convenient a fashion. Waid works too hard to wrap everything about that particular aspect of the story up in a neat package, leaving no trace, but also producing no answers. However, his character work remains strong as both Catherine and James reveal their primary motivations, conflicting ones at that. That conflict and attempted resolution is the best part of this issue, Waid unafraid to have them meet one another head-on, both convinced that they're right.

Minck Oosterveer's art has been one of the special treats of "The Unknown" and he goes out on a strong note. His work with darkness and shadows in the room behind the doorway is fantastic -- moody and evocative. He captures the sense of terror both Catherine and James feel at different times. His depiction of James towards the end of the issue as he tries to explain his action to Catherine is masterful and Oosterveer's best work on the series. I am looking forward to seeing what he does next.

"The Unknown" ends on a positive note, but maintains much of the mystery that drove the series forward. It is equally frustrating and strong, but definitely worth a look. Mark Waid really challenges himself and, while he doesn't fully succeed, I can't say that he fails either.