[CodeMephit]

Pure genius Congdar!! Thanks for the uber-fast reply.
Here is my take on how to do it. (Posting in case someone else may need to know how it's done.)

quest::signalwith(NPC_ID, SIGNAL_NUMBER, PAUSE);

NPC1 (Bob - ID#456)

sub EVENT_SAY{
  if($text=~/hail/i){
    quest::say("Hi $name.  This is my friend Joe.  Say hi, Joe.");
    quest::signalwith(123, 1, 2);
  }
}

sub EVENT_SIGNAL{
  if($signal == 2){
    quest::say("If you [need] us for anything, just let me know.");
  }
}

NPC2 (Joe - ID#123)

sub EVENT_SIGNAL{
  if($signal == 1){
    quest::say("Hey $name.");
    quest::signalwith(456, 2, 2);
  }
}

-Codemephit