Milo and Melissa join her dad to take a decommissioned fire engine to a fire engine museum, as chaos ensues with Murphy's Law. Cavendish and Dakota chase the fire truck down when their pistachios are ruined again, with Cavendish's mind solely targeted to Milo.
Milo and Melissa visit Mr. Chase at the Fire House as he is cleaning up an old fire engine that's to be delivered to a museum. As usual Mr. Chase is apprehensive about Milo's presence, but is impressed when he learns about Milo's considerable knowledge, and agrees to let the pair ride with him. Meanwhile, Balthazar Cavendish and Vinnie Dakota have received another pistachio-guarding assignment, only to find that their newly assigned vehicle is a tandem bicycle, which Cavendish sees as yet another instance of their superiors demeaning them. The fire engine goes out of control as Mr. Chase is driving it to the museum, and smashes Cavendish and Dakota's new bike; spotting Milo, the pair chase after him with Cavendish determined to find out the truth about Milo.
Milo puts his best efforts into keeping the engine from crashing or causing any severe destruction, though they do end up dragging an old trolley car that's been converted into a diner. Cavendish and Dakota board it and confront Milo, but since he is not a time-traveling agent he has no idea what they're talking about; he then acts to rescue several cats, one of whom bears more than a passing resemblance to Cavendish. The pair ends up being thrown off the engine after the trolley car becomes detached, and the engine finally comes to a stop in front of the firefighting museum tangled with a Tyrannosaurus Rex display from the Natural History Museum that arouses popular interest. Mr. Chase then admits that he and Milo have more in common than he had first thought, as Milo's efforts to contend with Murphy's Law are not unlike his own career as a firefighter.
For a full transcript of "The Little Engine That Couldn't", click here.
The image gallery for The Little Engine That Couldn't may be viewed here.
The dinosaur is the same dinosaur that was frozen in the Phineas and Ferb episode "It's About Time!".
The cat that resembles Cavendish got a big liking from fans, who dubbed him "Catvendish", "Balth Jr." and even "Balto"
The stripes on the American Flag outside the fire department are arranged in reverse. (They're supposed to go red white red, not white red white.
When Milo rings the bell just before asking to drive, his hand clips in front of the rope instead of around it after pulling it down.
Right before the fire engine starts to knock down the strip mall signs, as it's turning the corner, Balthazar's body disappears.
The three people standing in the breezeway between the Natural History Museum and the fire Engine Museum suddenly disappear.
In the courtyard between the two museums, in the foreground, a man's yellow shirt and blue pants change to brown and tan.
The four people in the foreground of the museum courtyard change dramatically in relative size to one another and to the grid etched in the concrete.
WWII Arial Combat - One of the falling cats is seen standing erect and saluting. There are several reports of downed pilots doing this after they bailed out of their plane, particularly in the earlier part of the war.