The Search for the Thief

The Mystery of The Invisible Dog

The Three Investigators gradually narrow a crowded field of neighbors until timing, motive, and routine identify the person behind the crimes.

increasing

Bearing strength in each event

decreasing

A Building of Suspects A Building of Suspects from "The Mystery of The Invisible Dog". A Building of Suspects A small resident circle Fenton Prentice names the few tenants still in town during the holiday.

A Building of Suspects from "The Mystery of The Invisible Dog". A Building of Suspects A small resident circle Fenton Prentice names the few tenants still in town during the holiday.

A Building of Suspects A small resident circle Fenton Prentice names the few tenants still in town during the holiday. Their routines and access make the apartment building a natural field of inquiry. Suspicion without proof The boys must distinguish eccentricity from criminal behavior. Knowing someone is odd or secretive cannot substitute for evidence.

The First Suspect The First Suspect from "The Mystery of The Invisible Dog". The First Suspect An exposed snoop Black stains reveal that Mrs Bortz has entered Prentice’s apartment and handled his belongings.

The First Suspect from "The Mystery of The Invisible Dog". The First Suspect An exposed snoop Black stains reveal that Mrs Bortz has entered Prentice’s apartment and handled his belongings.

The First Suspect An exposed snoop Black stains reveal that Mrs Bortz has entered Prentice’s apartment and handled his belongings. Her copied key explains the ordinary intrusion. A partial solution Prentice regains control of his apartment, but Jupiter Jones knows this does not explain the shadow. Clearing one mystery leaves the investigation open.

The Apparent Wanderer The Apparent Wanderer from "The Mystery of The Invisible Dog". The Apparent Wanderer A double presence Sonny Elmquist appears asleep in his apartment while a figure resembling him seems to haunt Prentice’s den.

The Apparent Wanderer from "The Mystery of The Invisible Dog". The Apparent Wanderer A double presence Sonny Elmquist appears asleep in his apartment while a figure resembling him seems to haunt Prentice’s den.

The Apparent Wanderer A double presence Sonny Elmquist appears asleep in his apartment while a figure resembling him seems to haunt Prentice’s den. The contradiction points away from ordinary entry. A new investigative lead Bob Andrews consults specialists at Ruxton University. Their account of astral wandering offers a possible explanation, but not yet proof of Elmquist’s role.

The Remaining Suspects The Remaining Suspects from "The Mystery of The Invisible Dog". The Remaining Suspects The field narrows Harley Johnson has an alibi for the burglary, and Sonny Elmquist was asleep.

The Remaining Suspects from "The Mystery of The Invisible Dog". The Remaining Suspects The field narrows Harley Johnson has an alibi for the burglary, and Sonny Elmquist was asleep.

The Remaining Suspects The field narrows Harley Johnson has an alibi for the burglary, and Sonny Elmquist was asleep. Gwen Chalmers and Mrs Bortz have been attacked or removed from the immediate scene. Routine becomes evidence Jupiter Jones compares the remaining tenants’ knowledge and schedules. Alex Hassell and John Murphy become the crucial alternatives.

A Five O’Clock Clue A Five O’Clock Clue from "The Mystery of The Invisible Dog". A Five O’Clock Clue A routine rules out a suspect The ransom is to be collected at five, precisely when Alex Hassell feeds the neighborhood cats.

A Five O’Clock Clue from "The Mystery of The Invisible Dog". A Five O’Clock Clue A routine rules out a suspect The ransom is to be collected at five, precisely when Alex Hassell feeds the neighborhood cats.

A Five O’Clock Clue A routine rules out a suspect The ransom is to be collected at five, precisely when Alex Hassell feeds the neighborhood cats. Jupiter Jones realizes Hassell could not safely be absent then. The final deduction The same schedule that makes Hassell conspicuous clears him and points to Murphy. The ordinary timetable of a neighbor becomes decisive forensic logic.

The first morning of the investigation

The day the marked desk is examined

The night the boys keep watch

After the hospital visits

The day the ransom instructions arrive