The Transient High-Energy Sky and Early Universe Surveyor (THESEUS) is a space mission concept currently under Phase A study by the European Space Agency (ESA) as candidate M5 mission, in view of a launch opportunity in 2032. The current assessment phase will be concluded in mid-2021.

Within this dedicated scientific conference, the THESEUS science case will be presented through dedicated review talks, discussing the status-of-the-art knowledge on GRB science, early Universe studies, gravitation wave physics, and transient Universe phenomena in general. The development status of the instruments on-board THESEUS will be reported and discussed, together with the current assumptions for the mission profile. Contributed talks are expected to enrich the program and suggest further exploitations of the THESEUS instrumentation in many other fields of the modern Astronomy, Astrophysics, Cosmology, and fundamental physics. Through this conference, we aim at strengthening the involvement of the community in the project and boost even more the synergies being developed between THESEUS and all other facilities operational in the 2030s in the multi-wavelength domains.

The event is promoted by the THESEUS consortium and the Science Study Team, appointed by ESA in 2018, plus the leading scientific Spanish representatives of the THESEUS collaboration.