  I propose a double-twist texture with local smectic order, which may have
been seen in recent experiments. As in the Renn-Lubensky TGB phase, the smectic
order is broken only through a lattice of screw dislocations. A melted lattice
of screw dislocations can produce a double-twist texture as can an unmelted
lattice. In the latter case I show that geometry only allows for certain angles
between smectic regions. I discuss the possibility of connecting these
double-twist tubes together to form a smectic blue phase.
