clues:

previously:
On the morning of day four, Dove had found Nate dead in a closet with a knife plunged into his heard.
While the group was trying to figure out what happened to him, other strange things began to happen.
Poppy had found blood smeared on the wall upstairs in Alexandria, Dove, and Poppy's room.
All of the doors and windows locked.
While the group listened to Tess trying to break out, the house went on total lockdown. Metal doors blocking all entryways.

•°•

The next morning you wake up to a sealed envelope on the kitchen counter.

dear guests:
sadly our dearest friend Nate had to leave us yesterday.
Each day there will be some sort of riddle you and your friends will have to solve. You have until 10:00 that night to solve it.
If right, somewhere in the house a way to get out will be presented to you.
If wrong: let's just say the number of people in the room will start to get smaller.
When you have your answer, write it down on a piece of paper and stick it in this envelope.
There is a small slit in the wall in the laundry room.
Drop the envelope in there
Best of luck to all of you
-A

My thunder comes
before my lightning
My lightning comes
before the clouds
my rain dries all the land
it touches
What am I ?