I think everyone agrees this is a bet here OTR.
Hero: (Covers)1/3NL on a Saturday night @ around 1am. Hero is playing well, mixing it up in different spots, almost always raising preflop, taking most pots down after a c-bet or a well-timed double barrel. Was up two BI until got overflushed playing suited connectors by a villain not involved in this hand. Q4cc > 98cc. This was about 20 hands ago. No signs of tilt apparent.
Villain: ($450) ~40 yo white guy. He plays rather straight forward. Only 1 hand notable between hero and villain. Hero raised AQ and villain called in position. Flop was K74cc. I c-bet he called. Turn was a K. I double-barreled, he min-raised, I obviously folded. I haven't seen him bluff or get out of line. A different hand when he flopped 2 pair against a different villain, he raised the flop on a coordinated board.
Limper: ($200) Scared money & terrible. Hadn't seen him raise preflop once. ~21 yo. Did a lot of l/c. Just rebought after l/c, c/c, c/c, c/c 2 pair vs better 2 pair. My target in this hand.
The hand:
Hero is in CO with K

9
Pre-flop:
(Villain is on button. SB & BB are LP and have been folding to my button & CO raises a ton.)
Limper limps from MP2, Hero raises to $15 (my standard raise), Villain OTB calls. Blinds fold. Limper calls.
No reads from either. Looked casual. Villain's range is 22+,AT+,sc. Limper could have anything
Flop: ($49) T

9

3
limper checks, hero c-bets $30, villain thinks maybe 5 seconds before calling, limper folds
Turn: ($109) 5
hero leads $60. Villain tanks after I bet. I take a look at him, and I get the distinct feeling he's hollywooding and has a monster. He looks supremely comfortable and confident and looks like he's contemplating a raise. He very smoothly calls. Internal monologue tells me I need to hit my flush here.
River: ($229) 9

Effective stacks: $345
Hero bets $115, villain thinks for maybe 3 seconds, then shoves.
It's $230 more to call a pot of $689.
Hero?