Here's the card text:

-- Neutral --
Obsessive Inmate
--------------------
Type: Character
Cost: 3
Skill: 3
Icons: CII
Subtype: Independent
Attribute: Willpower
Game Text: Obsessive Inmate does not un-commit from a story until that story is won.

Here's how I assume the ability to work if Obsessive Inmate was committed to a story in a previous turn:

a) If the active player decides not to add any characters to any story, the story with the Obsessive Inmate is not resolved.

b) If the active player decides not to add any characters to the story with the Obsessive Inmate (as a defender), but adds character to one or more other stories, the story with the Obsessive Inmate is resolved, as well.

c) In every other case the story with the Obsessive Inmate resolves as normal.

Is this correct?

That seems right. The rules state that the story phase ends if the active player doesn't commit. Otherwise, all stories resolve.

I thought it was in the rules or the FAQ that all stories resolve, even if the only character was somehow removed from the story?

This point was debated a long time ago, but if I do remember well, resolution occurs if characters are removed, because there was a character that gets commited in a story at the step "Active players commits his character" of the story phase. Thus the story must be resolved.

The problem of the inmate being that the owner of the character cannot uncommit it, so he has no "commitment step" to start the resolution for the story concerned. That's why b) stated that there need to be at least one character committed to a story by the active player in a way the story to resolve, as the "resolution step" depends on the existence of the "commitment step".

Thanks for the confirmation, everyone!

PRODIGEE said:

That made zero sense to me

Okay, so let's say I commit 3 characters to the story The Call of Cthulhu, including Obsessive Inmate. Let's say the opponent places no characters on their side, therefore I go unchallenged, and win 3 success tokens. After I win all the struggles, does every character uncommit except for the inmate? Then during the entire next turn of the opponents, the Inmate just stays committed to that story?!

Okay, sorry if I'm not clear enough, sometimes my english is really poor.

So, let's figure out the rules (p.13). There is a board where every step of a turn is described.

Look at the Story phase.

There is a step for attackers commitment, one other for defenders and you may notice that there are actions windows. If you read carefully the Attacker commitment step, you'll se this sentence :

"If the active player commits no characters to a story, the story phase
ends immediately. Proceed to step 6: End of Turn."

So, no caracters commited, no more story phase. In case attackers commit characters, it continues.

A character being unable to uncommit can't commit again, right ? So, if he's still on a story, you did'nt fulfill what this step was all about : committing.

Am I clear enough this way ?

Concerning your questions :

After I win all the struggles, does every character uncommit except for the inmate? Yes, in case no text specified you can.

Then during the entire next turn of the opponents, the Inmate just stays committed to that story?! yes, that's it !