  A multiple wavevector (Q) reconstruction of the Fermi surface is shown to
yield a profoundly different electronic structure to that characteristic of
single wavevector reconstruction, despite their proximity in energy. We
consider the specific case in which ordering is generated by Qx = [2{\pi}a, 0]
and Qy = [0,2{\pi}b] (in which a = b = 1/4) - similar to those identified in
neutron diffraction and scanning tunneling microscopy experiments, and more
generally show that an isolated pocket adjacent to the nodal point knodal =
[\pm {\pi}/2, \pm {\pi}/2] is a protected feature of such a multiple-Q model,
potentially corresponding to the nodal 'Fermi arcs' observed in photoemission
and the small size of the electronic heat capacity found in high magnetic
fields - importantly, containing electron carriers which can yield negative
Hall and Seebeck coefficients observed in high magnetic fields.
