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Signatures of vertical disequilibrium have been observed across the MilkyWay's disk. These signatures manifest locally as unmixed phase-spirals in$z$--$v_z$ space ("snails-in-phase") and globally as nonzero mean $z$ and $v_z$which wraps around as a physical spiral across the $x$--$y$ plane("snails-in-space"). We explore the connection between these local and globalspirals through the example of a satellite perturbing a test-particle Milky Way(MW)-like disk. We anticipate our results to broadly apply to any verticalperturbation.  Using a $z$--$v_z$ asymmetry metric we demonstrate that in test-particlesimulations: (a) multiple local phase-spiral morphologies appear when stars arebinned by azimuthal action $J_\phi$, excited by a single event (in our case, asatellite disk-crossing); (b) these distinct phase-spirals are traced back todistinct disk locations; and (c) they are excited at distinct times. Thus,local phase-spirals offer a global view of the MW's perturbation history frommultiple perspectives.  Using a toy model for a Sagittarius (Sgr)-like satellite crossing the disk,we show that the full interaction takes place on timescales comparable toorbital periods of disk stars within $R \lesssim 10$ kpc. Hence suchperturbations have widespread influence which peaks in distinct regions of thedisk at different times.  This leads us to examine the ongoing MW-Sgr interaction. While Sgr has notyet crossed the disk (currently, $z_{Sgr} \approx -6$ kpc, $v_{z,Sgr} \approx210$ km/s), we demonstrate that the peak of the impact has already passed.Sgr's pull over the past 150 Myr creates a global $v_z$ signature withamplitude $\propto M_{Sgr}$, which might be detectable in future spectroscopicsurveys.

Snails Across Scales: Local and Global Phase-Mixing Structures as Probes of the Past and Future Milky Way