In 1910 Manhattan, Victoria Van Brett, a bitter spinster heiress lives an isolated life with her sister Caroline. Her domineering urges go into overdrive when their half-brother Rip brings a new bride home to the family’s gloomy Fifth Avenue mansion, built by their late industrialist father. The title refers to a secret soundproofed chamber that the villainess uses to entrap her enemies.

Egyptologist, Dean Lambert, accused of car-theft, skips bail and begins a cross-country trek to join a group in New York headed for Egypt. With the police close on his trail he gets in and out of scrapes along the way.

Don Cesar De Vega crosses swords with a vicious member of the Queen's Guard, and steals the affection of a young heiress. When the officer frames the young upstart for murder, Don Cesar fakes his own death and retreats to the crumbling ruins of the family castle he plots his vengeance.

Rigby, Larribee, and Grant each have one third of Bill Joyce's map locating his gold mine. The three plus Joyce's sister Helen head for the mine. An accident with a runaway horse carrying supplies leaves them stranded in the desert with very little water.

A nobleman vows to avenge the death of his father by the hands of pirates. To this end, he infiltrates the pirate band; Acting in character, he single-handedly captures a merchant vessel, but things are complicated when he finds that there is a beautiful young woman of royal blood aboard.

After he inherits some money, Harold Bissonette ("pronounced bis-on-ay") decides to give up the grocery business, move to California and run an orange grove. Despite his family's objections and the news that the land he bought is worthless, Bissonette packs up and drives out to California with his nagging wife Amelia and children.