Dresser Industries, Inc. (Dresser) (plaintiff), a manufacturer of oil-well drill bits, was a potential defendant in a class-action lawsuit for conspiring to fix the prices of drill bits and fraudulently concealing its conduct (Drill Bits case). Stephen Susman and his law firm, Susman Godfrey (Godfrey), were lead counsel for the plaintiffs in the Drill Bits case. At the same time, Susman and Godfrey were also representing Dresser in two pending lawsuits related to (1) antitrust violations and tortious interference with contract (CPS case) and (2) asbestos in a Dresser building (Cullen Center case). Godfrey advised Dresser that it was lead counsel for the plaintiffs in the Drill Bits case and that Dresser was a potential defendant. Godfrey also notified Dresser that, if replaced, it would help transition the CPS case and Cullen Center case to new counsel. However, Dresser chose not to replace Susman and Godfrey in the two pending lawsuits. Dresser was later added as a defendant in the Drill Bits case. Dresser moved to disqualify Susman and Godfrey as lead counsel for the plaintiffs in the Drill Bits case. The district court denied the motion to disqualify, relying on the Texas Disciplinary Rules of Conduct to hold that there was no legal or factual relationship between the Cullen Center case and the Drill Bits case, and that any similarity between the CPS case and the Drill Bits case was immaterial. Dresser petitioned for a writ of mandamus.