Part 1 - Overview on volcanic unrest.- Significance of unrest.- Past experiences.- Part 2 - Geophysical and geochemical insights on unrest and precursory activity.- Volcano Seismology: detecting unrest in wiggly lines.- Volcano geodesy and multiparameter investigations.- Volcanic gases and low temperature volcanic fluids.- MONITORING CAPACITY: obvious and hidden problems.- Part 3 - Magma dynamics: Lessons from experiments and models.- Storage and ascent of magma.- Magma rejuvenation: Insights from numerical models.- Crystals, bubbles and melt: critical conduit processes revealed by numerical models.- Interaction between magma and hydrothermal system.- The magma laboratory: Constraining unrest mechanisms.- From unrest to eruption: Conditions for phreatic vs. magmatic activity.- Geochemical and isotopic investigations in the light of unrest.- Magma mixing as a prelude to unrest.- Part 4 - Bridging the gap between science and decision-making.- Legal governance.- A Warner paper incl Cost benefit.- Recognizing and tracking volcanic unrest: a probabilistic approach.- Probabilistic tools for hazard assessment and risk management.- Deterministic vs. probabilistic forecasts.- Perspective on global practices of communication and decision-makers' needs.- Social resilience and compliance during unrest crises.- Outreach and education.- Volcanic Unrest Simulation Exercises - guidance for future exercises.- Glossary.- INDEX.