Former employee of a nursing home alleged sexual harassment. Her employment agreement included an arbitration agreement. She moved to compel arbitration and the nursing home opposed, arguing plaintiff failed to meet a condition precedent and because plaintiff waived her right to arbitration when she commenced a civil action instead of initiating arbitration. Plaintiff argued the nursing home’s objections should be addressed and the court agreed. Arbitration was compelled. Plaintiff then contended that four other defendants who were not parties to the agreement should also be compelled to arbitrate because they were “her joint employer or single employer … Plaintiff states that all of the corporate defendants have the same principal place of business and the exact same board of directors. Plaintiff contends that all of the defendants to this action were her employer and that they operated as a single employer and or joint employer within the meaning of the law. As a result, she argues that they are all governed by the written arbitration agreement she signed.” Citing CD Partners, LLC v. Grizzle, 424 F.3d 795 (8th Cir. 2005), and Thomson-CSF, S.A. v. American Arbitration Ass’n, 64 F.3d 773 (2d Cir. 1995), the court found that a willing signatory seeking to arbitrate with a non-signatory that is unwilling must establish at least one of the following theories: 1) incorporation by reference; 2) assumption; 3) agency; 4) veil-piercing/alter-ego; and 5) estoppel. Plaintiff moved for limited discovery to establish one of these theories, which was granted.