The Ambassador's Death

"Magic is an age-old force; as powerful as the wind, as quick as lightning and as deadly as any crossbow, and all should respect it at all times. It is neither good nor evil, only the user is either. They should use it for good to help all of man, elf, dwarven and any other kind, yet as we all know, more use it for the good of the dark one and themselves.
Forty years almost to the date after the death of the Hakorns, Kathryn finds her eldest child dead, in a locked room and a vial of poison sitting on the chest near his body, but his parents, his wife and his King, swears it was not suicide! Then how come he is dead?
Kathryn and Macaith have to become detectives to find out why. Was Tralia threatened again? Was the family? What had their son gotten himself into that cost him his life?