Very few things can stand up against them both. 

Hm. So it seems.

At least until they get all the way up to the stone blocking the entrance to the actual tomb, which is covered in an immensely complicated blood ward that is apparently completely impenetrable.

Well, she's got flimsy and pencil, and plenty of time - she can at least spend time while Ellyn's expected in prayers examining it, picking apart the symbols and math. 

It seems to be encrypted somehow, or just entirely unrelated to any theory they've seen before. Ellyn gets fed up after a while, and starts throwing her own blood over it, trying to break it by force.

"Try my blood," she suggests, when this inevitably leads to Ellyn getting a little anemic. She's been taking notes for Ellyn on what attempts have what results. (There's not much.) "Using a non-necromancer's blood might at least ellicit a different response..." She has so many books that she's just kinda permanently moved down here; she's got a couple of them on troubleshooting and reverse engineering unknown wards open. (There's some A/B tests with different kinds of blood, which are generally considered basic with both poor specificity and poor sensitivity, also a lot of variation by practitioner, and only identifying stupidly broad categories, but they've got nothing else at this point.)

(She's also got every single book on encryption she could find, especially the older paper books, and has started dodging Aiglamene, doing all her exercises down here when she needs a break, even sleeping with her head pillowed on a - usually open - book. If she has to figure out this theory from the ground up, she will, no matter how bad of a headache it gives her - out of pride or spite as much as anything else at this point. (Her notes contain a lot of potentially novel theories by now, ones that failed initial tests for this fucking ward but might pan out later. She is dreaming about wards, only sometimes helpfully.))

"I seriously doubt that will do anything."

"Whether or not it does will give us information, though." She scowls down at her notes. "Brute forcing it isn't working. But..." Squint. "If it's keyed - that's the big thing A/B testing with different blood kinda works on according to this," she nudges the book on high security encrypted wards (which is itself encrypted, because the author thought he was funny; breaking that code took her a fucking week). "If it's at all different that raises the chance it's keyed, and you can sometimes at least narrow down the shape of the key... Like picking a lock." Gideon has pretty extensive experience with getting through locks despite lacking a key. "Or like brute force breaking encryption - and it's shown no sign of adaptive defenses yet, so might as well do this the incredibly boring way." 

Siiiiiiigggggghhhhh. It's the best idea they've had in a while, much as Ellynhark's frustration wants her to deny it. She's not getting anywhere with her current approaches and she is... trying... to take Gideon at face value. So.

"Fine," she says, grabbing the lancet. "Give me your arm."

Arm: is proferred.

Ellyn slices it expertly, collecting the blood in a plex container.

She doesn't react, other than smiling fondly. (Something about this is... Nice.)

She does keep her tools sharp, so it wouldn't have hurt much. But blood is best fresh from the vein, so Ellyn turns quickly to the stone and dips a finger to begin painting.

...But as soon as she touches the ward, it begins unraveling and the stone shifts with a creak. "What the fuck?"

" - ?!?!"

"Why the fuck did that work?!" She throws her pencil at her pad of flimsy in professionally offended frustration. 

"I don't know! It shouldn't have!" And then Ellyn has to back up hurriedly as the door begins to swing open.

She's outside of probable blast radius so doesn't need to scramble back, though she does get up and collect her most essential notes and blank flimsy and her cast aside pencil in case they need to dart through. She also continues complaining. 

"That's total fucking bullshit - unless it is keyed and I matched it somehow - using someone else's blood, using a non-necromancer's blood - some other trait like blood type - " She scribbles that thought down. "But fucking why?! That isn't secure!" She grabs the encrypted wards book and glares at it. "It reacted immediately so it didn't just give out, but usually you'd also need an action, so somebody can't just steal your blood - wait when did that become best practice - " Angry scribble. 

Ellyn is ignoring her in favor of looking at what the open door reveals: a faint salty tang to the air, a deep and wide pool of water, an island in the center of the pool, a stone altar on the island, a coffin-shaped block of ice on the altar, a burry figure in the ice, chains running from the figures limbs through the ice off the island down into the water.

She'll stop complaining in favor of looking for more traps. (This is the Ninth House. There's always more traps.)

There don't seem to be.

Ellyn is altogether more interested in getting across the pool to the island. No path, so it looks she'll have to swim for it.

This is So Suspicious. 

She'll set aside her book and notes with her robes. (No sense getting them wet, or having them weigh her down.) "Let me go ahead, in case something tries to eat us?" she tries to suggest as she's putting things aside, though it comes out as a bit of a dubious question.  

"There won't be anything else in here," she says, dismissively, not waiting.

She rushes to catch up. 

The saltwater is cold, but there are no lurking monsters or hidden currents to drag the girls down into the depths. They're able to make it safely to the island, and there on the altar lies

the body of a woman, cold and still as death in her prison of ice and her chains,