Detect Evil. Detect Magic. Stare at the creepy blood. 

"That's not actually fresh blood. I think it's some kind of haunting. I'll try an exorcism."

She's practiced exorcisms before, but this is her first real one. She walks in a circle around the bloodstain, chanting, invoking Pharasma as the foe of undead and the restorer of the natural order, and Iomedae as the foe of all Evil, calling for their aid in ending whatever distortion of life and death has taken place here. 

The concept of exorcisms is an old one, but the procedure has been refined over the centuries to make it stronger and more efficient, both in terms of the ability of lower-circle clerics to deal with larger hauntings and in terms of the wisp of intervention budget, not quite the same as a spell but not so different either, provided by the gods being prayed to.

Yes, yes, all right.

Iomedae can be so incredibly annoying about Justice and Efficient Resource Allocation but "ma'am respectfully you have a metric quintillion god dollars and I have like thirty-two and I understand that you care about different things than I do but would you at LEAST bother spending them on things YOU don't like if I TEACH MY PEOPLE TO HELPFULLY POINT YOU DIRECTLY AT THEM" was, you know, fair. 

Most things like this, against a first-circle cleric, get up again later; but it is not power, that moves Pharasma to look exactly where you are pointing. It is skill. To do this exactly right, what you need is to be the sort of person who sits through the very boring classes in seminary where you drill a thousand fine variations of language for each possible thing that can go wrong in the world, most of which you'll never meet, and devote exactly as much seriousness to each one as to the exciting ones about military history, and who calls up that knowledge not because you happen to be very gifted at memorizing things, but because it's very important to you, to do things right, when you do them. 

Which is to say, you need to be Samora of Lastwall. 

This particular haunt will not be moving again. 

Detect Evil. Detect Magic. Staaaare.

"Okay, now it's just a regular bloodstain."

"Oh, well done," says Marshall, in the mildly bemused tone of someone who did not think it was possible to do that but does in general expect magic to do things he didn't think were possible like five times a day. 

What next? 

Onward and upward! The next door is locked, but when they poke around, the key turns out to be in the rubble near where they fought the giant bugs, so that's no problem. What's at the top of this lighthouse?

Rows of black metal bars encase this circular chamber like a cage. Shimmering waves of force flicker between the bars and gives the illusion that softly glowing glass encases this entire area.

The room appears empty save for a human-sized encasement of glass and iron that flickers and glows with an unsettling, almost nauseating pale blue shimmer—Gauntlight’s lantern!

There does not appear to be any way to interact with the lantern from here; it is very obvious, both to detect magic and to detect evil, that it is powered from below. 

Well, they had to check. She reports this and they can . . . go back down, she guesses, because there's nothing else up here. Time to go looking for trouble somewhere else above ground.

Further searching will yield: in the adjacent room to the one with the ill-fated staircase, there's what was clearly once a secret door, covered by a rotted tapestry which no longer particularly hides it. It goes east, into somewhere they have not been. 

Does anything on the other side show up to Detect Evil? They're going in either way, but it's nice to get a hint about how much combat to expect.

There is definitely something Evil over there. 

Alright. This time they're going to do a good job and not mess it up. She warns the others and they head in, Samora and Marshall first with Tris behind them.