The Sarton Investigation
The Caves of SteelElijah Baley’s assignment becomes a contest to discover what happened in Spacetown and whether he can pursue the truth without losing his position.
increasing
Bearing strength in each event
decreasing
The Murder Assignment

The Murder Assignment
A political emergency
Elijah Baley learns that Roj Nemennuh Sarton, a Spacer scientist in Spacetown, has been killed by a blaster. The case threatens relations between Earth and the Outer Worlds.
A dangerous commission
Baley must solve the crime before the murder becomes an excuse for indemnities or intervention. His assignment carries a promised promotion, but also a robot partner he distrusts.
The investigation begins as both detective work and a test of Earth’s competence.
The Humanlike Partner

The Humanlike Partner
First encounter
At the Spacetown approach, Baley expects a recognizable machine and discovers that R. Daneel Olivaw appears human. The mismatch unsettles his assumptions before the investigation has begun.
A partnership under pressure
Daneel receives a police rating and equal standing, forcing Baley to work beside the very kind of robot he fears could replace him.
Their unequal trust becomes the investigation’s daily tension.
The Impossible Route

The Impossible Route
A blind spot
Baley assumes that Spacetown can only be reached through its guarded entrance. Daneel points out that both the City and Spacetown open onto countryside.
An unsettling possibility
An Earthman could have crossed open ground at night, bypassing the barrier. Baley resists the theory because the open country feels almost unthinkable to a City dweller.
The case turns toward the psychological limits of urban life.
The Suspects Reverse

The Suspects Reverse
An accusation collapses
Baley accuses R. Daneel of being a human disguised as a robot, then imagines a Spacer conspiracy. Demonstrating Daneel’s mechanical body defeats both theories.
The investigation returns home
The evidence and the absence of a weapon point back toward New York City. Baley must stop looking for guilt in Spacetown and examine the people around him.
His certainty fails before his detective work can advance.
The Murder Explained

The Murder Explained
A mistaken target
Baley reconstructs the killing as a failed attempt by Julius Enderby to destroy Daneel. Without his glasses, Enderby mistook Roj Nemennuh Sarton for the robot and killed the wrong man.
Physical confirmation
A transmitted image shows glass fragments by the dome door. Comparing them with Enderby’s glasses turns a psychological theory into tangible evidence.
The original case ends with an accidental murder exposed.
Early in the story, three days after the killing
The day Baley meets his partner
The first evening of the investigation
After Baley visits Spacetown
Near the climax, shortly before midnight