Near TPK in my 4e game

Last Tuesday's installment of my 4e game ended with our heroes in very perilous straits.  We ended the session with Beautiful Bob the half-gibbering mouther psychic (Ardent) and Hammer the warforged barbarian both below 0 HP and surrounded by snakemindflayers, presumably about to have their intelligences consumed.  The party's other member, Tilia the albino minotaur warden, had previously merged her body into the giant honeycomb mushroom brain that the snakemindflayers worshiped and called MotherMind.   At the end of the session Tilia had entered a lucid dreamstate to attempt some psychic healing on MotherMind.  Tilia was trying to sooth the nightmares of MotherMind and she called upon the energy of Bob and Hammer (with whom she shares a permanent telepathic link that was forged with alien energy technology some time back) to help her.  Bob and Hammer had both just dropped below 0 HP that round and lost consciousness so I gave them the option of joining Tilia in the shared dream when she called upon their energy.  They both took me up on that, so we will start next session with all three PCs in a shared dreamscape with MotherMind.

A few notes on how we got into this predicament:

*  The party allowed themselves to be led to the caverns of the snakemindflayers by a guide, knowing the entire time that the snakemindflayers wanted Tilia to merge with the MotherMind to fulfill an ancient prophecy about a white cow that featured prominently in the snakemindflayer religion.  The party had also gleaned that the snakemindflayers intended to kill the rest of the party and consume their intellects.

* The previous session, the party had initially parlayed with the first few snakemindflayers that they ran into... until suddenly jumping them and massacring them in one round.  For some reason the party decided to take a five minute rest in the same cavern that they just fought in, apparently deciding that no alarm had been raised despite knowing that the snakemindflayers and the mushroom men thralls that they had just killed had a psychic connection with MotherMind.

*  When the party's five minute rest was interrupted by a legion of approaching snakemindflayers and thralls, they decided to confront them rather than attempt to flee (although to be fair the only obvious direction to flee would have been deeper into the caverns of the snakemindflayers and toward MotherMind).

*  Faced with overwhelming numbers the party willingly marched with the snakemindflayers deep into their living mycelial city and Tilia willingly merged herself with MotherMind.  At that point the rest of the snakemindflayers politely asked Hammer and Bob to accompany them back to the ritual sacrifice chambers so they could fulfill their destiny of being consumed.  Hammer and Bob didn't want to comply.

*  The party soon learned that the metallic rods that the snakemindflayers all carried were some kind of technological laser weapon.  Hammer learned that getting shot with lots of lasers hurts.