"Well, I'm not a wizard, but in that case it sounds like we should either try it today or wait until we're home and bring it to a specialist, does that seem reasonable?"

"That sounds reasonable to me. I defer to the two of you" (he nods at Fernando and Mateo) "as to what sort of resources he was likely to be carrying, and whether they justify the risk."

"If he was carrying a teleport scroll, that seems worth the risk of doing it now to have that as an option for an emergency need to escape.  Well... two of us would need to fit into the bag I don't think a sixth-circle's teleport is strong enough to get six people, even assuming he scribed it at maximum strength.  And if the bag isn't particularly high capacity we could use two reduce persons.  So what are the odds he had a scroll?"

"He was the sort to always have a back up plan, so he almost certainly has at least one teleport scroll, if not more.  Probably lots of other scrolls for contingencies?  Oh and he would have had at least one scroll of Malediction, you know, for, uh-"

Mateo nods to the wizard.  And if there are two scrolls of Malediction, Matero is definitely going to stop feeling the twinge of guilt.

"So I'm in favor of opening it sooner rather than later."

These seem like a nice bunch of people, but 12 or 24 days or whatever is plenty of time to accidentally forget a loosely implied offer to split the loot.

In that case, they can do some basic set-up (in case there turn out to be any of the kind of traps best handled by throwing the item into a small hole or something), and re-cast their orison buffs just in case, and cast a second Rope Trick, and ensure they've positioned the bag correctly, and then send out the first Unseen Servant to investigate.

If the leader had the spare energy (at the moment he is quite busy struggling against less developed demon larvae, his demonic pact has given him a substantial but not overwhelming advantage) to recount his thought, he might say something like this:

Most of the scenarios it was worth it to secure his bag of holding against involved internal mischief, backstabbing, and plotting.  Killing a genuinely threatening internal rival is reasonable.  Killing a pawn of rival would be wasteful.  Even someone as lowly as a second-circle wizard is, in the long run, quite valuable.  Valuable enough to use one of the more expensive trap options he considered as opposed to a cheaper trap.

So have a Symbol of Pain.  He rigged this symbol via subtle modification to the bag of holding to be the first thing that comes out if an unauthorized user fails to use the failback command word or gesture.  Hopefully this will teach a valuable lesson to any pawns while leaving them alive.

And for more serious thieves, well, just keep trying to dig through the bag and see what happens...

The Unseen Servant is a mindless force undeterred by pain! It keeps trying to dig through the bag. What happens?

Baphomet doesn't care about divine treaties restricting his clerics to such a precisely constrained and from one of these clerics he had learned an obscure symbol.  Have a Symbol of Exsanguination!   Enough blood loss sustained over multiple rounds can kill even seasoned adventurers.  And it will leave plenty of evidence for him to track them down later.

It won't actually trigger for the Unseen Servant, undead and constructs were on his mind when he setup the triggering conditions for this one.

And if that doesn't work... his bag is probably completely stolen or lost, and Explosive Runes don't cost anything to cast.  Have six of them in enlarged writing all on one extra large sheet of parchment.  And have fun looking through his books and notes, he has a scattering of more explosive runes across his writings, tucked away were he can conceal or reveal them with a quick page turn.

The Unseen Servant can't read, so unfortunately it won't be triggering any of those. It sorts the items according to the simple-enough-for-a-mindless-construct rules it's been given and puts the Symbols into a small hole.

There are over a dozen scrolls and typical adventurer's supplies: rope, a tent, rations, water bladders, hand ax, dagger, various other mundane odds and ends.  Among the more ornate or unusual items (and thus likely magical): a pearl, a decorated goblet, an odd foot long iron bar with many protrusions and spikes, a headband, a rope studded with bits of metal, another headband with spikes, and a third headband.  And finally three notebooks and various papers.

Once the first Symbol has had time to exhaust itself, they can peer at the remaining items with a Detect Magic. The results won't be entirely reliable, of course, but they can still be somewhat informative. (The untriggered Symbol is, at this point, safely in a hole.)

There are lots of auras of abjuration, faint, but on the heavier end of faint, so likely third circle.  6 of them on one big sheet of paper, more of them in the notebooks and papers.  And if he is particularly discerning he can make out that they have force effects, so almost certainly Explosive Runes.  He had better be careful not to read any of them.

The scrolls will need to be individually identified, but none of them have that aura of abjuration so they should be safe to read?

The pearl has an aura of strong transmutation, almost certainly a standard pearl of power.  The goblet has a faint aura of conjuration, it can create water.  The iron bar also has a transmutation aura, it looks like it effects the bar itself, allowing it to transform into a variety of forms?  One of the headband's is a standard headband of wisdom. 

The other items are weirder.  The rope is something like a combination of a backwardly done metamagic rod with a transmutation spell built into it (or maybe it responds to a transmutation spell).  The obvious spell is rope trick.  One of the other headbands is almost a standard intelligence headband, except it is critically flawed, as if the creator tried but failed to cram an Owl's Wisdom into it.  So it interferes with the wearer's wisdom, effectively reducing it by somewhere around a half to a fourth of the amount Owl's Wisdom increases it.  The other headband is complicated... in it's typical operation it only works half as well as the least sort of standard intelligence headband, but some conditions can strengthen it temporarily up the full strength of a Fox's Cunning.  Also, other conditions cause it to inflict moderate to extreme pain on the wearer.  Also it is cursed so it can't be taken off by the wearer.

The symbols dropped in the hole are deep enough that their aura can't be seen without taking them out at least partially.

He's looking over carefully too.  Lots of Explosive Runes, their caution was well worth it he doesn't see any notable illusions, but that's not a guarantee.  They should all compare what they see in case one of them lucks out and sees through a Magic Aura... maybe they should use an identify tomorrow before they try using anything, just to be safe.  Or maybe one of them should use their bonded object spell now on it?

That seems reasonable to him. His inclination is that once they've done that, they should use the Unseen Servant to bring over one scroll at a time, while Elettra (as the person with by far the best reflexes) 'reads' them to ensure they don't have a disguised Explosive Runes or a Sepia Snake Sigil, after which he and Fernando can attempt to decipher what each scroll actually does. Does anyone have objections or modifications to propose? (For that matter, does Mateo know whether the leader ever made use of cursed scrolls that immediately activate when deciphered?)

"He liked fiddling with item designs... it sounds like the sort of thing he would be capable of doing, but I think he had spells for trapping scrolls?  Like one of the ones you already mentioned, with the Explosive Runes or the Sigil Snake.  Oh, I recognize the rope from a description, it directly casts Rope Trick occasionally, and once a day it can make a rope trick (either cast on it or cast by it) last longer so someone less powerful can make their rope trick last long enough or if he needed his to last all day."

He looks to Elettra.  "Are you that confident in your reflexes?  Do you want a Cat's Grace for the extra boost?"  If she's confident he's got no objections.

She nods. "I'd take one, it can't hurt."

“Alright.”  He casts it.

“The rest of us should all be ten feet from you and the scroll… well, let’s make that twenty feet just in case of metamagic.”

She nods, accepts a Guidance from Justice, and repositions herself accordingly. The Unseen Servant starts bringing over the scrolls one-by-one.

None of the scrolls have any Explosive Runes or Sepia Snake Sigils (or Incendiary Runes for that matter).

Scrolls should be a shareable resource that can he give to other cult members that could put them to use, and working around Explosive Runes would be an obstacle to that!  In principle you can instruct someone how to avoid specific explosive runes, but in practice you should allow for moderate odds someone fucks up following even simple instructions (he'll allow for low odds in the event they have a decent headband and decent starting mental abilities, but not no chance).

In that case, he and Fernando can attempt to decipher the scrolls. What do they find?

Two Teleports, two Maledictions, a Lesser Geas, a Delay Poison, a Water Breathing, a Remove Blindness/Deafness, a Lesser Restoration, a Magic Aura (scribed with the full potency of a fifth-circle instead of the minimum to put it on a scroll), an Invisibility (scribed at the potency of a sixth-circle), two Air Bubbles, two Infernal Healings, and a non-standard version of Black Tentacles squeezed down to third-circle (further analysis will suggest they do more of a flailing random grasp than a proper grapple).

(The Grasping Tentacles scroll was going to be a gift/bribe to the errant third circle wizard if they took their punishment/correction with the appropriate attitude, assuming he didn't have to maledict them.)

Hearing that there is not one but two Malediction scrolls makes him confident he made the right choice.