  We present the most general (six-helicity) angular analysis of Bs -> V_1 (->
P_1P'_1) V_2 (-> P_2P'_2) (V_i is a vector meson, and P_i, P'_i are
pseudoscalars). We focus on final states accessible to both Bs and Bsbar --
these are mainly bbar -> sbar penguin decays. We also derive the most general
decay amplitude, and discuss the differences between it and that used by LHCb
in its analysis of Bs -> phi phi. In the standard model, all CP violation is
predicted to be small, so that the simple measurement of a sizeable
CP-violating observable indicates the presence of new physics. A full fit to
the data is not necessary. By determining which of the CP-violating observables
are nonzero, one can learn about the structure of the underlying NP. Finally,
we apply the angular analysis to Bs -> K^{*0} Kbar^{*0}, and show that there
are numerous CP-violating observables that remain in the untagged data sample.
