Plume Coteries diplomatic craft
From Tardis Wiki, the free Doctor Who reference
Plume Coteries diplomatic crafts were space-time vessels with interdimensional capabilities which appeared as "big metal spheres".
In contrast to their more famous use of giant multi-coloured birds as steeds at earlier points of history, by the time the Plume Coteries participated in the negotiations surrounding R.M.S. during the War in Heaven, the Bookkeeper ambassador travelled via such a craft. (PROSE: A Farewell to R.M.S. [+]Loading...["A Farewell to R.M.S. (short story)"])