According to state police, who shared the encounter on Facebook, the lost, frightened dog was dangling dangerously in and out of traffic when officers arrived.
But when they tried to coax Lexi off the road, the errant animal bounded back into the rush of traffic.
It was time for some serious police work - a coordinated effort from not one, but three agencies: Massachusetts State Police, officers from the Methuen Police Department and the Massachusetts Department of Transportation.
First, every lane of traffic was closed.
Then it all came down to state trooper Malachy Higgins' granola bar.
Come on, Lexi, you know you love granola bars.
Lexi went after that granola bar so hard, she leapt right into the cruiser, knocking over the officer's coffee and even turning on the police siren.