Peladon Concealed Door Wedge Rock

The Doctor selects a fist-sized granite wedge lying near the tunnel mouth to hold open the concealed doorway, allowing unobstructed passage for himself and Jo to enter and exit before the rock is presumably retrieved or left for others to remove.

Though not named in the text, this wedge rock aligns with the described object: naturally striated and positioned to hold open the hidden entrance. Its red-stained surface and angular shape make it a tactile guide for Grun and a physical marker of secrecy, guiding the Doctor’s entrance into the forbidden space.

A large rock, likely repurposed from the tunnel walls, functions as Hepesh's improvised weapon when he hurls it at Grun's head to break free from the mute champion's restraining grip. The rock's weight and angular shape make it a devastating tool, illustrating how the quiet tunnels become a battleground where even mundane objects are transformed into instruments of violence.