The Museum's Hidden Ceremony
Foucault's PendulumCasaubon's museum visit moves from scientific wonder to paranoid interpretation and finally becomes the site of the fatal ceremony he fears.
increasing
Bearing strength in each event
decreasing
The First Encounter

The Suspended Sphere
A fixed point
Casaubon sees the Pendulum in the church at Saint-Martin-des-Champs and imagines it as the one stable point beneath a moving universe. Its scientific demonstration acquires spiritual force for him.
Belbo's influence
He remembers Belbo's description of the instrument and suspects the place holds a deeper significance. Wonder and prior suggestion combine, weakening his confidence in ordinary explanation.
The Museum as Code

A Building Reinterpreted
Symbols in exhibits
Casaubon reads machines, mirrors, instruments, and the hall of glass as parts of an encoded design. Familiar exhibits become signs of hidden forces and secret historical continuity.
Private delusion
His interpretations reveal how the Plan has altered his perception: he turns each coincidence into confirmation. The museum no longer seems neutral, though no evidence verifies his reading.
The Pendulum's Reversal

The Ceremony
A public ritual
The conspirators gather around a relocated Pendulum and demand that Belbo disclose his supposed secret. Their ceremony mixes theatrical ritual, coercion, and competing claims to authority.
A final refusal
Belbo rejects Aglie's offer and refuses the crowd's demand. He is hanged from the Pendulum, while Casaubon watches from hiding and escapes through the sewers.
At the opening of the novel
During Casaubon's first night in the museum
Near the novel's climax