$109: Is this a Bluff?!?

[MSUcougar]

NL Texas Hold'em $100 Buy-in + $9 Entry Fee Trny:15802265 Level:3 Blinds(25/50) - Friday, September 16, 22:32:24 EDT 2005
Table Table 11709 (Real Money)
Seat 2 is the button
Total number of players : 9
Seat 4: HERO ( $1080 )
Seat 10: ( $910 )
Seat 9: ( $885 )
Seat 3: VILLAIN ( $2035 )
Seat 5: ( $1360 )
Seat 1: ( $1215 )
Seat 6: ( $640 )
Seat 2: ( $620 )
Seat 8: ( $1255 )
Trny:15802265 Level:3
Blinds(25/50)
** Dealing down cards **
Dealt to HERO [ Qs Jc ]
folds.
folds.
folds.
folds.
folds.
calls [50].
calls [50].
VILLAIN calls [25].
HERO checks.
** Dealing Flop ** [ Qh, 8s, 4s ] (POT 200)
VILLAIN checks.
HERO bets [85].
folds.
folds.
VILLAIN calls [85].
** Dealing Turn ** [ 6h ] (POT 370)
VILLAIN checks.
HERO bets [200].
VILLAIN calls [200].
** Dealing River ** [ Kd ] (POT 770)
VILLAIN bets [700].
HERO ????


No prior reads, but villain took a LONG time thinking before making the river bet. My stack on the river was 745.

Call or fold?