This guide is suitable for current RuneScape and Old School.
Talk to a guard near Sinclair Mansion (the mansion north of Seers' Village).
The guard will inform you that Lord Sinclair has been murdered, but they do not know who the killer is. If you choose to assist them, he will tell you to talk to the family about information that could help you solve the mystery.
Investigating the Crime Scene
Head to the most eastern room of the mansion, this is the crime scene. From this room, take the Pungent Pot that's sitting on the table and the Criminal's Dagger from the centre of the room. A "smashed window" on the eastern wall can be investigated to find the Criminal's Thread.
Once you have the 3 pieces of evidence, head to the chicken coop in the south west area of the manor. Talk to the gossip to find out that the Poison Seller has been around recently.
Talk to the poison seller, at the tavern in the western part of Seers' village. He will tell you that he sold poison to each of the family members.
Return to Sinclair's Mansion and talk to the family and servants about the poison. Each person will tell you what their motive for using the poison was, and the location they used it.
- Anna - Used the poison on the compost heap.
- Bob - Used the poison on the beehive, located on the west side of the manor.
- Carol - Used the poison to clean the drain outside of the mansion door.
- David - Used the poison to kill spiders upstairs.
- Elizabeth - Used the poison on the mosquitoes at the fountain.
- Frank - Used the poison to clean the crest on the Mansion's outer wall.
Investigate each of the places until you find one that hasn't been touched with poison.
Once you have found out who is lying, return to the Guard who will tell you that more evidence is required.
Gathering more Evidence
Search the barrel in the room of the person that was lying to find an item that belongs to that person.
On the west side of the mansion, you will find a shed. Inside of the shed, you will find sacks. Investigate the sacks to get 2 pieces of flypaper.
Head to the kitchen and use your pot on a barrel to get flour. Use the flour on the Criminal's Dagger and then use flypaper on the dagger to get a set of fingerprints. Repeat this process with the suspects item, then use the suspects fingerprint with the original fingerprints to determine that they match.
Return to the guards to get your reward.
Congratulations! Quest Complete!
Guide Made by: Wood Bowl
Corrections submitted by: Doctor Shemp, Deathslayer, DaDa, Dx1438, Nick D, Wise Choice, Power of Five