Before the series started, the consensus was that the Senators would struggle to score goals, but would do okay defensively and might have the edge in nets with the 'hotter' goaltender. Conversely, the Canadiens might be at a disadvantage size-wise, but had three lines that can score and the powerplay might serve to keep Chris Neil honest.
Unfortunately, Carey Price has still not worked his way out of his funk, so the Sens are indeed holding the stronger hand in that regard, and it's also providing them with all the offence they need.
Meanwhile, the David Desharnais and Tomas Plekanec lines are underperforming, to describe it charitably, and with Lars Eller out, there go our three scoring lines.
The powerplay is not clicking, so Chris Neil has free rein to grab on to Brendan Gallagher's head as if it was a coconut and he were a baboon (not a big stretch).
For the Canadiens to win, they have to return to their gameplan and play to their strengths. They need to skate and apply pressure together as a team, bury their chances, and make the Sens pay for their transgressions on the powerplay. Carey has to perform. No excuses.