The Montreal Canadiens surprisingly got involved in the Erik Karlsson trade sweepstakes, though it was not to acquire the star defenseman. They were able to play mortgage broker for the Pittsburgh Penguins and San Jose Sharks to make the financials of the deal work out for both sides.
Essentially what the Canadiens did was take on some money and a couple of contracts so the Penguins had the cap space to add Karlsson to their lineup. They also added a second round pick and a prospect named Nathan Legare in the process.
The two players the Habs acquired are not unknowns around the league.