Davey realises that their unseen assailant is Old Jimmy, who fled to Serenity after his brother and friends were executed in the Freelands.
He’d heard that the King was trying to make peace with Serenity and had planted the medicine to try and disrupt the truce.
When they weren’t killed on the village green, he took matters into his own hands.
Deborah is still trying to revive the king, so Davey is on his own.
Old Jimmy ceases his toying with them – shooting from outside the barn – and comes in to finish them.
Davey manages to sneak up on him.
They fight and Davey manages to get the better of him, blasting him to pieces with the assault rifle.
Davey passes out and wakes up in the Freelands hospital.
The King is in the next bed, but Davey thinks he is dead.
The doctors explain that they are both fine, they just need rest and antibiotics.
Next chapter (6.1) is here
Chapter 7.1 (the next chapter chronologically) is here