Star Trek: Deep Space Nine

Episode: DS9 486 - Return to Grace

A boxy Cardassian freighter (pronounced "gru-MAUL"), captained by the disgraced Dukat in 2372, sent to escort Kira to the Korma intelligence conference before being converted to a warship and overtaking a Klingon Bird-of-Prey and being detonated with the captured Klingons. It has at least five levels.