When a project manager joins a project midway and identifies issues with dependencies and communication, the first step should be to consult the communications management plan. This plan outlines how project communications will be planned, structured, implemented, and monitored for effectiveness1. It includes key points such as defining the audience, requirements, and communications schedule, which are essential for ensuring that all team members are adequately informed of impacting changes1. By consulting this plan, the project manager can address the communication issues systematically and align with the established project management practices.