Zack was deceiving them both.
Eleven o'clock was the family hour for going to bed at Baregrove Square.
Zack's first proceeding on entering his room was to open his window softly, put on an old traveling cap, and light a cigar.

It was December weather at that time; but his hardy constitution rendered him as impervious to cold as a young Polar bear.

Having smoked quietly for half an hour, he listened at his door till the silence in Mr.Thorpe's dressing-room below assured him that his father was safe in bed, and invited him to descend on tiptoe--with his boots under his arm--into the hall.

Here he placed his candle, with a box of matches by it, on a chair, and proceeded to open the house door with the noiseless dexterity of a practiced burglar--being always careful to facilitate the safe performance of this dangerous operation by keeping lock, bolt, and hinges well oiled.

Having secured the key, blown out the candle, and noiselessly closed the door behind him, he left the house, and started for the Haymarket, Covent Garden, or the Strand, a little before midnight--or, in other words, set forth on a nocturnal tour of amusement, just at the time when the doors of respectable places of public recreation (which his father prevented him from attending) were all closed, and the doors of disreputable places all thrown open.
One precaution, and one only, did Zack observe while enjoying the dangerous diversions into which paternal prohibitions, assisted by filial perversity, now thrust him headlong, He took care to keep sober enough to be sure of getting home before the servants had risen, and to be certain of preserving his steadiness of hand and stealthiness of foot, while bolting the door and stealing up stairs for an hour or two of bed.