  I present an informal overview of several recent results about Euclidean
saddle points sourced by axion fields in quantum gravity (AdS/CFT), such as
wormholes, their extremal "D-instanton" limits and their under-extremal
singular counterparts. Concerning wormholes we argue they cannot contribute to
the path integral because a stability analysis suggests they fragment like
other super-extremal objects. For concrete AdS/CFT embeddings the Euclidean
saddle point solutions are neatly described by geodesic curves living inside
moduli spaces and can typically be solved for using group theory. Our working
example is $AdS_5\times S^5/\mathbb{Z}_k$ and allows for smooth Euclidean
wormholes. For the supersymmetric D-instanton-like solutions we seem to find a
match with the instantons in the dual $\mathcal{N}=2$ quivers. This match even
extends a bit further to self-dual instantons without supersymmetry.
