Molos can dig around in the control panel and pull out the amulet.
The hall leading out of this chamber appears to now connect the security sublevel with the upper dungeons where you were before, establishing a new exit through one of the doors marked 'do not enter' that you passed earlier.
Once you escape the sublevel, retracing your path through the upper dungeon and back to the surface is simple. Meleren and Shechera shrug a little bit and thank you for the help. "We're certainly glad to be seeing daylight again; we weren't sure we'd be making it out of there after our companions started falling. We were lucky to have come across you in the end I suppose."
Initially, Ambrus Valsin is stunned into silence by your report, then heaps simultaneous praise and disapproval on you—he commends you for surviving a much tougher test than intended, but criticizes you for not immediately leaving and reporting in upon discovering the security sublevel. In the end, though, both the deed and discovery stand out, and local Packminders Pathfinders—many of whom begin in-depth investigation and cataloging of the hidden complex—regard you with high esteem. In the months to come, explorers seeking more hidden secrets swarm the Red Redoubt.