Red round clock switches sit in the Clock Tower rooms of Castlevania: Belmont’s Curse, and they are how you get past the moving machinery that fills the place. Each one slows the gears, saws, crushing blocks and collapsing stairs around it for a short window so you can run or jump through.
Quick answer: Walk up to a red clock switch, press R1 (PC: E) at the “INTERACT [R1]” prompt, and move straight away while the screen holds its green tint.
How the clock switches work
The switch is a red clock. Stand next to it and the prompt “INTERACT [R1]” (PC: E) appears. Press R1 and the screen takes on a green tint with a clock-face burst. That is your signal the effect is running.
The hazards are slowed, not stopped. Gears, saw blades, crushing blocks and the collapsing staircase keep moving, just slowly enough to pass. There is no timer or icon in the HUD while the effect lasts, so treat the green tint as a cue to move the moment you press.
A failed obstacle run puts you back beside the clock. Activate it and try again, with little ground to make up.
Entering the Clock Tower from the bridge
The route across the Clock Tower Bridge runs past a large glowing clock face mounted on the bridge. Before you touch it, equip Soul Harvest, the spell of The Shadow, which is the card from Death. Interact with the clock using INTERACT, R1 (PC: E), and a green clock-shaped swirl appears, opening the way on toward Isaac. Without Soul Harvest equipped, the clock is Death’s trap and sends Rose into a false Master’s Quarters and the bad ending, Belmont’s fall; this is not a game over, and play resumes at the Mirror of Life in Mechanic’s Ascent.
Clock Tower rooms with clock switches
The tower holds 7 red clock switches, met in this order of rooms: Clock Keeper’s Atrium (2), Bridge of Haste (1), Eastern Summit (2), The Gauntlet (1) and Steps of Time (1).
Clock Keeper’s Atrium
Huge gears turn throughout the Clock Keeper’s Atrium, with spinning saw blades sweeping around them. The chamber has two red clock switches; at the entrance, use the first one, marked “INTERACT [R1]” (PC: E). Cross once the gears slow down. The exit is high on the right; reach it with the yellow grapple anchors.
Bridge of Haste
Conveyor belts and moving saws fill the Bridge of Haste, where skeleton archers and an armoured knight also block the way. Activate its single red clock switch with INTERACT, R1 (PC: E), just as before, to slow the machinery. Cross the belts while taking on the enemies along the route.
Eastern Summit
Heavy stone blocks crush their way down a tall shaft, blocking the climb. Activate the red clock and scale the slowed blocks. At the shaft’s exit, use the second clock to slow the pillars on the floor below, then run left beneath them. Mistime the crossing and you’ll be crushed and sent back to the clock.
The Gauntlet
Spiked blocks and platforms move through this room, enclosed by spiked barriers beneath a spiked ceiling. Use the red clock switch marked “INTERACT [R1]” (PC: E) to slow the blocks, and stay on the platforms as you cross. Ahead, a hallway lined with spinning saw blades takes you to a pedestal on the right.
Steps of Time
The long staircase breaks apart as you climb. At its base, activate the red clock with R1 (PC: E); the screen turns green. Run east to the exit before the stairs give way.
