The Murder Weapon’s Journey
The Caves of SteelThe movement of the blaster connects the hidden crossing into Spacetown, the killing, and the later attempt to frame Baley.
increasing
Bearing strength in each event
decreasing
A Weapon Missing

A Weapon Missing
No blaster recovered
The Spacers check their weapons and find none fired in recent weeks. A thorough search of Spacetown yields no murder weapon.
Two routes remain
The killer must have hidden the blaster or carried it away. The absence becomes a central constraint that any convincing theory must explain.
A missing object structures the investigators’ entire search.
A Robot’s Possible Capacity

A Robot’s Possible Capacity
Food sac proposed
Baley imagines that a humanoid robot could conceal the missing blaster in its food sac and cross the countryside without difficulty. The theory appears to solve both the route and weapon problems.
Technical suspicion tested
Gerrigel’s analysis confirms Daneel’s First Law, while inspection reveals the harmless nature of his displayed weapon. The suspected hiding place and implied capability are not supported.
The weapon’s path must be found elsewhere.
The Crossing Reconstructed

The Crossing Reconstructed
A two-way transfer
Baley concludes that Enderby sent R. Sammy across the countryside with a blaster, entered Spacetown through the regular Personal, and received the weapon there. After the killing, R. Sammy carried it back.
A machine used as courier
The plan relies on robotic ability to cross open ground without the fear that would stop most City dwellers. The City’s own robot labor becomes a tool in a murder plot.
The murder weapon’s route identifies the hidden partnership behind the crime.
The Weapon Reappears

The Weapon Reappears
A different radiation device
An Alphasprayer destroys R. Sammy, and investigators trace it to the Williamsburg power plant. The device is not the original blaster but becomes the weapon used to cover up the first killing.
A false trail planted
The trace points toward Baley because he crossed the plant during his escape. The second weapon supplies a misleading connection to the first crime.
The cover-up borrows the logic of evidence to redirect suspicion.
The Two Crimes Connected

The Two Crimes Connected
One culprit, distinct acts
Baley connects the original blaster’s route to Enderby’s access and the later Alphasprayer to the frame against him. The first death was accidental, but the second destruction was deliberate.
Motive clarified
Enderby silenced R. Sammy because the robot knew enough about the first operation to endanger him. The weapon trail makes the cover-up part of the murder’s afterlife.
The full chain turns two apparent cases into one political crime.
During the first review of the crime scene
During Baley’s suspicion of Daneel
During Baley’s final explanation of the murder
The day R. Sammy is found destroyed
At the final confrontation near midnight