  It is a challenging task to explain, in terms of a simple and compelling new
physics scenario, the intriguing discrepancies between the standard model
expectations and the data for the neutral-current observables $R_K$ and
$R_{K^*}$, as well as the charged-current observables $R(D)$ and $R(D^*)$. We
show that this can be achieved in an effective theory with only two unknown
parameters. In addition, this class of models predicts some interesting
signatures in the context of both $B$ decays as well as high-energy collisions.
