Pokerbros, .50/1, $60 effective (hero covers.) Villain is a complete unknown and there is no information available to hero. Though, the population is pretty fishy.
OTTH
Hero opens CO $3 K

Q

and only villain calls in BB.
Flop ($6.50): Q

J

6

. Villain checks, hero bets $4.50 and villain calls.
Turn ($15.50): K

. Villain checks, hero bets $8, and villain calls.
River ($31.50): 7

. Villain donks $13 with another $31.50 behind. Hero?