At the start of Harry Potter and the Goblet of Fire, how was Alastor Moody captured? Why was he able to be captured by Wormtail and Barty Crouch Jr? After all Alastor Moody was the most powerful Auror, and single-handedly captured dozens of Death Eaters.
Also, didn't he place protective enchantments around his own home?
Barty Crouch Jr. describes how he and Wormtail captured Moody while being questioned under Veritaserum. He says that Moody struggled, and there was a commotion, but they did still manage to subdue him. From this, it sounds like it was difficult to capture Moody, though they were able to.
“Wormtail and I did it. We had prepared the Polyjuice Potion beforehand. We journeyed to his house. Moody put up a struggle. There was a commotion. We managed to subdue him just in time. Forced him into a compartment of his own magical trunk. Took some of his hair and added it to the Potion. I drank it, I became Moody’s double. I took his leg and his eye. I was ready to face Arthur Weasley when he arrived to sort out the Muggles who had heard a disturbance. I made the dustbins move around the yard. I told Arthur Weasley I had heard intruders in my yard, who had set the dustbins off. Then I packed up Moody’s clothes and Dark detectors, put them in the trunk with Moody, and set off for Hogwarts.”
- Harry Potter and the Goblet of Fire, Chapter 35 (Veritaserum)
In addition, Barty Crouch Jr. had the Polyjuice Potion so he was able to drink it quickly and then (as Moody) convince Arthur Weasley that everything was fine.
From an entirely unrelated series:
“You want to send in harnessed ferrets through a laundry vent?” Augustine clearly had difficulty coming to terms with that idea.
“Yes,” Cornelius said.
I blinked. “Wouldn’t the vent be secured by an alarm?”
The three of them looked at me as if I’d suddenly sprouted a second head.
“It doesn’t make sense to secure a laundry vent,” Rogan explained. “It’s too small and it opens into a dryer.”
...
...
“I’m more paranoid than Baranovsky,” Rogan said. “My laundry vents aren’t secured. But I’d imagine there is a metal grate over them.”
“Does anybody else find this whole idea of a ferret heist mildly absurd?” Augustine looked around the room.
“Grates are not an issue,” Cornelius said.
“Can your animals handle screws?” Augustine asked.
Cornelius met his gaze. “Let’s assume that I spend as much time training my animals and honing my magic as you do practicing your illusions.”
“How confident are you that this will work?” I asked Cornelius.
He smiled at me.
“Let’s do it,” Rogan said.
- White Hot, by Ilona Andrews
As an intelligent rodent, Wormtail possess unparalleled advantages when it comes to breaking and entering. Once he was inside, he could disable the alarms and let Crouch in. He probably wouldn't be able to turn off everything, but all he needs to do is get Crouch in fast enough to get the jump on Moody before he's fully awake. Two fully prepared wizards against one half-asleep one is no contest, even if the half-asleep wizard is Alastor Moody. Even so, he put up enough of a fight to be noticed by the neighbors, which is pretty impressive.
