by the Unseen Hook with a Twitch Upon the Thread

I've been watching the PBS Masterpiece Theater mini-series "Brideshead Revisited." Quite the Easter treat. One of the most poignant scenes is when Lady Marchmain is reading aloud the passage below from Chesterton's The Innocence of Father Brown to the family gathered in her drawing room.

The Evelyn Waugh-ite irony of this tableau is that the unspoken subtext is the group wondering how to respond to scoundrel son Sebastian's drunken binge behavior.

My own ironic delight is to think of us all as the thief-

each and all wandering a-stray,

but pulled back to penitence through the great Unseen Hook.

Long live Waugh!
Long live Chesterton!
Long live the God who seeks us all!

"Hallo, there!" called out the duke. "Have you seen anyone pass?"

The short figure did not answer the question directly, but merely said: "Perhaps I have got what you are looking for, gentlemen."

They paused, wavering and wondering, while he quietly went to the back of the cloak room, and came back with both hands full of shining silver, which he laid out on the counter as calmly as a salesman. It took the form of a dozen quaintly shaped forks and knives.

"You--you--" began the colonel, quite thrown off his balance at last. Then he peered into the dim little room and saw two things: first, that the short, black-clad man was dressed like a clergyman; and, second, that the window of the room behind him was burst, as if someone had passed violently through. "Valuable things to deposit in a cloak room, aren't they?" remarked the clergyman, with cheerful composure.

"Did--did you steal those things?" stammered Mr. Audley, with staring eyes.
"If I did," said the cleric pleasantly, "at least I am bringing them back again."
"But you didn't," said Colonel Pound, still staring at the broken window.
"To make a clean breast of it, I didn't," said the other, with some humour. And he seated himself quite gravely on a stool. "But you know who did," said the, colonel.

"I don't know his real name," said the priest placidly, "but I know something of his fighting weight, and a great deal about his spiritual difficulties. I formed the physical estimate when he was trying to throttle me, and the moral estimate when he repented."

"Oh, I say--repented!" cried young Chester, with a sort of crow of laughter.
Father Brown got to his feet, putting his hands behind him. "Odd, isn't it," he said, "that a thief and a vagabond should repent, when so many who are rich and secure remain hard and frivolous, and without fruit for God or man? But there, if you will excuse me, you trespass a little upon my province. If you doubt the penitence as a practical fact, there are your knives and forks. You are The Twelve True Fishers, and there are all your silver fish. But He has made me a fisher of men."

"Did you catch this man?" asked the colonel, frowning.

Father Brown looked him full in his frowning face. "Yes," he said, "I caught him, with an unseen hook and an invisible line which is long enough to let him wander to the ends of the world, and still to bring him back with a twitch upon the thread."