Most of the death slugs drilled through the upper pane of the window.
The lower pane was raised, the upper pane was fixed.
Maybe the upper pane slid down over the lower pane, too.
The lower pane had been pushed up behind the upper pane.
Flickering orange light played over the upper panes of glass.
Windows have a fixed upper pane with sliding sash below and louvers.
All windows are in pairs, with a diamond pattern in the upper pane.
In the sitting-room, Millie was standing on a chair and reaching up towards the upper panes of the window.
He took out a glass cutter, carefully removed a section of the upper pane, and reached through to open the lock.
An upper pane of the window was broken and the window was open.