Air date: January 28th, 2010 (UK), September 4th, 2010 (US)
It is the Fat Controller's birthday, and Thomas is sent to Maithwaite early to collect the Fat Controller and Lady Hatt to take them to the party. However, when Thomas arrives, he is very surprised to see the Fat Controller already there - and that he has a moustache and calls Thomas his friend. The Fat Controller is very jolly too and tells Thomas to take him to Whispering Woods. Thomas finds the Fat Controller's behaviour very strange and wants to ask him about his moustache, but he does not so as not to look so silly.
At Whispering Woods, the Fat Controller decides to play hide and seek with the children, much to the confusion of Thomas and Edward as they know the Fat Controller does not usually play with children. Once the Fat Controller is back on board Annie, he tells Edward to let the children have some more play time even though Edward is taking them to the party. Then, when Thomas stops at Bluff's Cove Junction, the Fat Controller jumps out and goes up to the signalbox and messes around with the levers, causing Gordon who is taking the important visitors to the party to go on an old line. Thomas finds this very strange indeed, but once again, he does not ask the Fat Controller about his behaviour because he does not want to look silly.
Thomas goes back to Maithwaite where the stationmaster scolds him for being late. The Fat Controller and Lady Hatt waited for Thomas, but as he didn't turn up, they had to take Bertie, who, unfortunately, had broken down. Thomas is very confused, but realizes that his passenger cannot be the Fat Controller; so he asks the question that he wanted to ask all day, and, to Thomas' surprise the passenger reveals himself to be Sir Lowham Hatt, the Fat Controller's brother. Sir Lowham Hatt wants to have some more fun, but Thomas knows that this is not the time for playing games, as they are late.
Thomas finds Bertie broken down, and the Fat Controller is cross with him until he sees his brother and scolds him instead for causing so much confusion and delay. Once the Hatt family are at the party, Thomas finds Edward and Gordon and helps them get to the party just in time. At the party, the Hatt brothers have fun, which makes Thomas happy.
Tropes featured in the episode:
- An Aesop: Always ask the person you wish to see why they act so odd so you know who you’re really seeing.
- Big Fun: Sir Lowham Hatt.
- Birthday Episode: The episode is set during Sir Topham Hatt’s birthday.
- Foolish Sibling, Responsible Sibling: Sir Lowham Hatt and Sir Topham Hatt respectively.
- Oh, Crap!: Thomas when he sees "Sir Topham Hatt" with a mustache.
- Out-of-Character Alert: Thomas notices “Sir Topham Hatt” has a mustache, laughs so hard his hat nearly falls off, and he even calls him his “good friend”.
- Polar Opposite Twins: Sir Lowham Hatt being the fun-seeking brother in contrast to the serious Fat Controller.
- Wham Line: "I'm not Sir Topham Hatt, I'm Sir Lowham Hatt — Sir Topham's brother!"
- What the Hell, Hero?: The stationmaster when Thomas is late and Sir Topham and Lady Hatt haven't arrived at the party yet.
