I'm going to start a D&D 5e campaign, and one of my players wanted the father of her character to be a legendary (or at least really exceptional) dwarven blacksmith having a link with Moradin.
She wants the disappearance of her PCs' father to be a trigger for going out of the mountain and going on an adventure to try and find him.
As she wanted the father to be a blacksmith with a link with Moradin, I thought he might be a Moradins' Forge domain Cleric, granting both a tangible link with the god and the smithing proficiency. And to be able to have some contact with his god, he'd have to be at least 10th level.
However, my player doesn't want the father to just disappear, but to be kidnapped for some lore reasons. And I'm worried about finding a realistic way to keep a level 10 (or higher) Forge Cleric in custody for a long period.
While this question about preventing a forge cleric from using Channel Divinity address a part of it, the cleric could still use his Divine Intervention to get help in some way.
Is there a RAW way to prevent a forge cleric from using his Divine Intervention to escape from custody?
The cleric has to be kept alive, and bonus point if the solution permits him to be exploited by his keepers to forge some items (even without his divine powers).
I'd like to avoid hand-waved solutions or indirect solutions (like taking a hostage or threatening him) as this would fall outside of expectations of this site and be considered opinion-generated answers.
The solution proposed can come from any official sources, be it a class feature, a spell, a monster ability, or anything as long as it's RAW and can be reliably used for an extended period of time. We're using the Forgotten Realms setting so it's a plus if it's compatible with it, but it's not mandatory.
The kidnappers could be anyone at my discretion, so there is no limit to the cost or rarity of the solution.