He had not admitted to himself that he was really going.

Now he knew.
Wednesday would be the night.

On Wednesday evenings his father had a service which prevented him from returning home until half-past eight.
He would go to Somerset's at half-past four, and would be expected home at half-past six; there would be no real alarm about him until his father's return from church, and he could, therefore, be sure of two hours' bliss.

For the consequences he did not care at all.

He was going to do no harm to anyone or anything.