Unsolved: Picnic Panic

Unsolved: Picnic Panic is a quest in the Fallout 76 add-on Wild Appalachia.

Quick walkthrough
Investigate the picnic site in Toxic Valley for the following clues:
 * Rat poison (empty)
 * Two bicycles, belonging to "Chelsea Wesley of Clarksburg" and Mary Tinley.
 * Mary Tinley's recording

Investigate the Wesley House in Clarksburg for the following clues. It is on the eastern edge of town towards the Clarksburg Shooting Club.
 * Chelsea's diary page - In the corner of the bottom floor (can't be picked up).
 * Cow's magnet (a kid's magnet and some loaded dice that respond to it) - Next to the diary page.

Investigate Mary Tinley's home in Clarksburg for the following clues. It is a broken trailer, partially submerged in toxic water, on the northwestern edge of town. Harvey Tinley still lives here, although he has been turned into a Ghoul. He will attack on sight.
 * Mary's diary page - In a backpack inside the trailer.