Prior research suggests people have trouble juggling effort across multiple projects with multiple partners. We investigated this problem, with an experiment where groups of four participants enacted the roles of police detectives. Each detective was assigned two homicide cases, each case with a different partner. To solve each case, detectives read their case documents and discussed relevant information with their partners. Half the groups used IM to communicate and the other half used an enhanced IM tool called Project-View IM (PVIM). PVIM lists partners and joint projects and lets users know what a partner is working on. We analyzed keystroke level computer activity and the content of conversations. Generally, work unfolded as follows: coordinate across cases, start first case, read documents, coordinate within case with partner, switch to second case, and so on, but with frequent interruptions. We describe implications of our findings for theories of multitasking.