Is he bluffing?

[Tvashtri]

Seat 1: Timmy Br ($143.60 in chips)
Seat 2: Pdoggie1 ($194.95 in chips)
Seat 3: Jeebuxx ($97 in chips)
Seat 4: jupiler1976 ($193 in chips)
Seat 5: IPlayAces ($100 in chips)
Seat 6: lunenoire ($72.10 in chips)
Seat 7: BarneyF ($157.95 in chips)
Seat 8: pipes1230 ($176.70 in chips)
Seat 9: Tvashtri [QD,KD] ($105.60 in chips)
ANTES/BLINDS
BarneyF posts blind ($0.50), pipes1230 posts blind ($1), IPlayAces posts blind ($1).

PRE-FLOP
Tvashtri calls $1, Timmy Br calls $1, Pdoggie1 folds, Jeebuxx folds, jupiler1976 folds, IPlayAces checks, lunenoire calls $1, BarneyF folds, pipes1230 checks.

FLOP [board cards KC,2C,JH ]
pipes1230 checks, Tvashtri bets $4, Timmy Br calls $4, IPlayAces folds, lunenoire folds, pipes1230 folds.

TURN [board cards KC,2C,JH,6D ]
Tvashtri bets $9, Timmy Br calls $9.

RIVER [board cards KC,2C,JH,6D,9C ]
Tvashtri checks, Timmy Br bets $35, Tvashtri ???

My check kinda gave him the opportunity to bluff me out, but when i saw that 3rd club fall, i just felt like it was a bullet. Its just such a large bet after a weak check, it makes it feel like he is jumping on a chance to bluff. Your move?

[Fnord]

QT is g00t, fold.