Speak with dead
From Ardrana
Upon casting a speak with dead spell, the caster is able to ask several questions of a dead creature in a set period of time and receive answers according to the knowledge of that creature. Of course, the caster must be able to converse in the language that the dead creature once used. The length of time the creature has been dead is a factor, since only more powerful casters can converse with a long-dead creature.
Even if the casting is successful, such creatures are as evasive as possible when questioned. The dead tend to give extremely brief and limited answers, often cryptic, and to take questions literally. Furthermore, their knowledge is often limited to what they knew in life.
Note: This version of speak with dead originally appeared in the 2nd Edition Player's Handbook for Advanced Dungeons & Dragons from TSR. Its use here is for the purposes of providing context for the campaign only.