Picking the ambush site and preparing it had fallen mostly on Zorian’s shoulders in the end. The aranea knew how to make traps and ambushes, of course, but most of them were based around lethal force or mind magic assaults. Considering that the third time traveler almost certainly knew how to counter aranean mind magic and that they wanted him alive, little of it was useful for their purposes. Thus it fell to Zorian to design something that would contain and disable their target, or at least distract them until the aranea could strip them of their mental defenses and do their thing. Kael contributed by helping Zorian make a mixture of powerful alchemical sedatives for disabling purposes and the matriarch served as his assistant since she was the most capable aranea when it came to structured magic and knew a lot about the local mana flow of the settlement. She would also be the one to lead the execution of the actual ambush with her fellow aranea, so she had to be extremely familiar with how the trap was going to work.
In the end, Zorian decided upon a three-part trap, set in the middle of the aranea settlement. The first part was a fairly exotic effect on the floor that turned stone temporarily liquid. The effect would only activate for a moment, immediately shutting off and turning the stone back into a normal solid state once the target sunk to their knees into the rock floor. As far as Zorian could tell, there was no easy way for a mage to get themselves out of the rock once the effect ended. The spell couldn’t be dispelled any more than the ashes of a fireball-destroyed book could be dispelled back into a pristine state, and trying to blast the rock off was liable to blow the caster’s legs along with it. The only convenient way of getting out was to phase or teleport out, which is why the second part of the trap was a dimensional lock that would shut down most dimensional shenanigans. Finally, the last part involved dousing the combat area with smoke infused with the powerful sedatives Zorian made with Kael’s help.
It was a bit simple, but Zorian had read that the best plans are always simple. Just in case, though, he had built backup traps in several other aranean caverns. These were a lot less sophisticated ones, though, and boiled down to ‘explosions’. A whole lot of explosions.
Aside from that, Zorian had made a great deal of combat equipment for the aranea participating in the ambush: shielding discs that they could strap on to their body to shrug off some of the weaker attack spells, stone cubes and alchemical vials that produced a variety of effects when set off, and some equipment for himself and a handful of mercenary mages that the matriarch discreetly hired as additional muscle during the ambush. Of course, in an ideal scenario Zorian wouldn’t have to fight anyone at all and the equipment he made for himself would be a useless waste of time… but really, what are the chances of an ideal scenario? Things had been going a little too well for him as it was.
As for the hunt for the cranium rats, that had actually been his own idea, and he had been pleased that he had thought of something the aranea, with all their connections and psychic might, hadn’t. The basic idea was to capture one of the rats and then use that specimen as a connection for divining the location of the rest of the rats. Not quite a novel idea to the aranea, but they thought heavily in terms of mind magic and tried to follow the telepathic links connecting the captured rat to the rest of the hive mind — something that quickly failed, since the main collective promptly cut the connection with any captured rats. Zorian, on the other hand, used good old locator spells — divinations meant to find and keep track of all sorts of things, so long as the caster had something connected with what you’re trying to find. A cranium rat, even if disconnected from the collective, was sufficient for those divinations to work. Zorian ended up following the connections until he located the main bodies of the cranium rat swarms (there had been 4 of them, as it turned out) and then, with a handful of aranea acting as support and psychic powers suppressant, herded them into tight formations that could be wiped out with a single fireball spell. By the end of the month, the cranium rats had been effectively wiped out.
When he was finished torching the fourth rat swarm, one of the aranea assigned as his body guard during the operation told him she finally understood why humans were supposed to be so scary and dangerous.