Fold this vs unknown?

I've never seen so much chasing in my life. Ive been seeing backdoor flush chases on paired boards, gutshot str8 chasing and everything else so maybe I'm seeing monsters but it really looked like a chase at best and slowplay at the worst.

***** Hand History for Game 2330320472 *****
$100 NL Hold'em - Friday, July 08, 14:21:50 EDT 2005
Table Table 54873 (6 max) (No DP) (Real Money)
Seat 2 is the button
Total number of players : 6
Seat 1: tbonelangdog ( $74.5 )
Seat 2: eliteG ( $387.7 )
Seat 3: AllInToWin04 ( $35.45 )
Seat 4: Monetix ( $251.25 )
Seat 6: SmackinYaUp ( $104.35 )
Seat 5: kraudo ( $99 )
AllInToWin04 posts small blind [$0.5].
Monetix posts big blind [$1].
** Dealing down cards **
Dealt to SmackinYaUp [ Ad Kd ]
kraudo calls [$1].
SmackinYaUp raises [$4].
tbonelangdog folds.
eliteG folds.
AllInToWin04 calls [$3.5].
Monetix folds.
kraudo calls [$3].
>You have options at Table 55491 (6 max) (No DP) Table!.
** Dealing Flop ** [ 7s, Ks, Kc ]
AllInToWin04 checks.
kraudo checks.
SmackinYaUp bets [$7].
AllInToWin04 folds.
kraudo calls [$7].
** Dealing Turn ** [ 8h ]
kraudo checks.
SmackinYaUp bets [$15].
>You have options at Table 55491 (6 max) (No DP) Table!.
kraudo calls [$15].
** Dealing River ** [ Ts ]
kraudo bets [$30].
>You have options at Table 55491 (6 max) (No DP) Table!.
SmackinYaUp folds.
kraudo does not show cards.
kraudo wins $85

Yep, I fold it. Either he's bluffing or hit his flush, and since you have no read I think you gotta give him credit for the latter.

Tough fold but I don't think he would bet that hard on a flush on a paired board. Since you don't have any reads its hard to tell.

Bet the turn harder... I know you want to get paid, but he's calling with something and you should make it expensive. Not sure about the river... I might have to pay that off just in case it's a weaker king or a bluff.