Blind battle on 4-flush board

[malteg]

Villain is unknown.


Poker Stars
Limit Holdem Ring game
Limit: $1/$2
8 players
Converter

Pre-flop: (8 players) Hero is BB with 7[img]/images/graemlins/spade.gif[/img] A[img]/images/graemlins/heart.gif[/img]
6 folds, <font color="#cc0000">SB raises</font>, <font color="#cc0000">Hero 3-bets</font>, SB calls.

Flop: 5[img]/images/graemlins/club.gif[/img] A[img]/images/graemlins/club.gif[/img] K[img]/images/graemlins/club.gif[/img] (6SB, 2 players)
SB checks, <font color="#cc0000">Hero bets</font>, <font color="#cc0000">SB raises</font>, Hero calls.

Turn: 4[img]/images/graemlins/club.gif[/img] (5BB, 2 players)
<font color="#cc0000">SB bets</font>, Hero ???

Call down or just fold?