ToME: the Tales of Maj'Eyal

So, should I bury myself in one of those newly vacant coffins ?

Use the Rod of Recall.

No, I killed myself out of principe. Still curious, if such layout was intended.

You seemed to be suffered by the problem what I'd experienced before, no way out portal.

The stairs disappear on purpose when you open the door at the end. Also all the doors to the coffin rooms disappear.

Out of curiosity, what principle had you kill yourself? You had your answer, and it was the correct intended answer so... some sort of Roleplay objection to using the basic mechanic?

Kind of. Fun thing is, I first got another date with Eidolon thank to some mettled archer, chosen ignominious escape onto world map and then come again through mausoleum’s forecourt to still everything back... Mere rod versus such a treacherous marvel of architectural thought ? No, only direct extraplanar intervention seemed appropriate enough for me.