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Causal set quantum gravity is based on the marriage between the concept of causality as an organising principle more basic even than space or time and fundamental atomicity. Causal sets suggest novel possibilities for "dynamical laws" in which spacetime grows by the accumulation of new spacetime atoms, potentially realising within physics C.D. Broad's concept of a growing block universe
in which the past is real and the future is not. To do justice to relativity and general covariance, the atoms must accumulate in a partial order, exactly the order that the atoms have physically amongst themselves. That this is possible is demonstrated by the Rideout-Sorkin Classical Stochastic Growth models. This proof of concept -- of the compatibility of relativity and ``becoming'' -- is, however, classical and is challenged by the global character of the physical world within a path integral framework for quantum theory. Out of the struggle to reconcile the global and local natures of the physical world may arise a quantal dynamics for causal sets.

In this talk I will focus on two topics concerning compact binaries that involve a neutron star companion: a) the fate of and observable signatures from merging white dwarf-neutron star (WDNS) binaries, and b) electromagnetic signals from black hole - neutron star (BHNS) binaries.WDNS systems - the neglected child among compact binaries - generate detectable gravitational waves (GWs) and may also generate observable electromagnetic (EM) signals. One of the most fascinating aspects about these systems is that they are known to exist, but the final fate of massive, merged WDNSs remnants is currently work in progress. Determining the fate of WDNS remnants will be important for interpreting observations from future transient surveys. I will review recent work that provides insight into the physics of WDNSs remnants. Black hole - neutron star systems are among the most promising sources for gravitational waves, and at the same time also possible sources of detectable precursor and aftermath EM signals. I will present recent the results from general relativistic force-free simulations of binary BHNSs and a type of EM precursor signatures expected from these systems.