Unreachable boss in the Maze

[Tom]

Hello

I returned from the East.
I found Nimisil by using Track. Alas, he is stuck inside a small room about 3-4 squares that is undiggable.
How can I get to him?
Will controlled phase door work?

[Faeryan]

Teleport/phase door, controlled or uncontrolled should work.

[Tom]

Teleport/phase door, controlled or uncontrolled should work.

Thx.
I have a pair of boots with Phase Door.
This rogue is on a mission and he can not use the runes so I hope for the boots.