Quotation from: The Chessmen of Mars

Written by: Edgar Rice Burroughs

"How was Gahan able to enter the throne room garbed in O-Tar's
trappings?" I asked.

"It was simple--for Gahan of Gathol," replied The Warlord. "With
the assistance of I-Gos he crept into The Hall of Chiefs before
the ceremony, while the throne room and Hall of Chiefs were
vacated to receive the bride. He came from the pits through the
corridor that opened behind the arras at the rear of the throne,
and passing into The Hall of Chiefs took his place upon the back
of a riderless thoat, whose warrior was in I-Gos' repair room.
When O-Tar entered and came near him Gahan fell upon him and
struck him with the butt of a heavy spear. He thought that he had
killed him and was surprised when O-Tar appeared to denounce
him."