An unexpected train and an unexpected leader. I was surprised by an eastbound crossing the Richelieu River on CN's St-Hyacinthe Sub not too long after CN 120 passed, it had NS 9512, CN 3080 & CN 9584 and perhaps 20-30 cars. I found out later it was CN 527, heading east out of Southwark Yard; 99% of the time CN 527 heads west out of Southwark Yard for the island of Montreal. While NS leaders are relatively common out of Montreal, they are rare this far east on the St-Hyacinthe Sub.