Spook's note

Spook sent a note to Vin after the events in Urteau, revealing that metal spikes can cause hallucinations and a presence behind them can twist a persons thoughts.

He inscribed it on a thin metal sheet, knowing that anything else could be altered. It describes the effects of Ruin on the mind of someone spiked with a hemalurgic metal. The note was intercepted by Marsh before it got to Vin.^{[citation needed]}

Content

“Vin, My mind is clouded.

A part of me wonders what is real anymore. Yet, one thing seems to press on me again and again. I must tell you something. I don't know if it will matter, but I must say it nonetheless.
The thing we fight is real. I have seen it. It tried to destroy me,and it tried to destroy the people of Urteau. It got control of me through a method I wasn't expecting. Metal. A little sliver of metal piercing my body. With that, it was able to twist my thoughts. It couldn't take complete controlof me, like you control the koloss, but it did something similar, I think. Perhaps the piece of metal wasn't big enough. I don't know.
Either way, it appeared to me, taking the form of Kelsier. It did the same thing to the king here in Urteau. It is clever. It is subtle.
Be careful, Vin. Don't trust anyone pierced by metal! Even the smallest bit can taint a man.

Spook.”

—Spook's note to Vin about Hemalurgy and Ruin