9:00 A.M.-10:00 A.M. - S1-E10

Corrected entry: Jack is on the phone with his wife and daughter, while CTU listens and tries to trace the call. When Eli enters the room where the women are being held, Jack tells CTU to mute the line so Eli can't hear them. When Eli finds the phone, he asks "who is this?". Jack responds with a threat that scares Eli into hanging up the phone. If the phone was muted, Eli shouldn't have been able to hear Jack.

Correction: As we find out later, Nina is in fact Yelena and is working for them, so she might not have muted the phone for the sole purpose of Eli finding it.