BOSTON - The Vancouver Canucks are heading home in search of answers after letting the Boston Bruins back in the Stanley Cup final.

Tim Thomas was unbeatable and Rich Peverley scored twice Wednesday as the Bruins steamrolled Vancouver 4-0, making the NHL's best regular-season team look ordinary for the second straight game and tying the series 2-2.

Boston outscored the Canucks 12-1 in the two games at hostile TD Garden. Alain Vigneault removed starter Roberto Luongo after he surrendered four goals on 20 shots in Game 4 and will now face more questions about whether Luongo or backup Cory Schneider will start Game 5 at Rogers Arena on Friday.

It's far from the only question hovering over the team.

A once-potent power play has disappeared as Vancouver failed to convert on six more opportunities and now sits at just 1-for-22 in the series. Two of those situations came in the first period when the Canucks were unable to solve Thomas and grab early momentum.

The team's star players have yet to make much of an impact in the series. Ryan Kesler, who generated Conn Smythe talk heading into the series, has just one assist in four games -- which is one more than captain Henrik Sedin.

The Bruins have been getting contributions throughout their lineup with goals from Michael Ryder and Brad Marchand to go with the pair scored by Peverley.

Thomas has been the best player in black and yellow, allowing just five goals on 145 shots in the series. He made another 37 saves in Game 4.