"I'm so glad you found the little rascal! I'm sorry that he nicked your...what was this...thing... again?", Mr. Scamander asked.
"A sonic screwdriver, quite handsy device. It's alright though, I got it back after all.", the Doctor answered benevolent. That was only one half of the story. The other half was that he was a bit fond of the creature that stole his sonic. What was it's name again? Miffla? Niethler? Niffler? Oh yeah, that was it.
"Oh, it's tea time, do you want to join me?", Mr. Scamander offered politely.
"I could handle a good cup. As much as I like Americans they really don't know how to make a strong cuppa.", the Doctor grinned.
Mr. Scamander, how the English man in New York had introduced himself before to the Doctor, put his suitcase on the floor and opened it. He looked around nervously but they were alone in a small aley.
The Doctor peered curiously in the suitcase. He couldn't identify any belongings, but something that looked like a ladder. And right, Mr. Scamander steped into the suitcase. The Doctor's eyes grew wide while the other man disappeared deeper and deeper in the suitcase.
Could it be? Nooo...but what if?
A brown-haired head popped out of the suitcase, "aren't you coming? I thought you're a traveller! I bet, you've never visited a place like this!", his eyes were sparkling. There was something in those eyes, something very familiar to the Doctor. He saw a bit of himself in this strange man's eyes. He must cared for someone or something very deeply, the Doctor thought.
"Allons-y!", he exclaimed, and followed Mr. Scamander into the suitcase.
After a few moments of silence he exclaimed something different: "It's bigger on the inside!"
Finally, after all this years, he understood the astonishment and admiration of his companions when they entered his Tardis for the first time.