In the story, when Alice and Bob suspect the presence of Eve, they introduce additional security measures and decoy signals to protect their entangled communication. These measures create disturbances and inconsistencies that can be detected by Alice and Bob. The presence of Eve and her attempts to intercept the communication cause a noticeable lag or delay in the exchange of information.<p>As Alice and Bob monitor the quality of their communication, they are alert to any unusual delays or disruptions that cannot be explained by the inherent uncertainties of the entangled particles themselves. This serves as an indication that someone else, in this case, Eve, might be attempting to interfere with their communication.<p>If Eve realizes that her attempts to measure and intercept the communication are becoming increasingly difficult or inaccurate due to the uncertainty principle and the security measures employed by Alice and Bob, she may eventually give up. When Eve ceases her interference, the communication between Alice and Bob returns to its normal state, without the disturbances and lags caused by her presence.<p>Thus, by being aware of the potential presence of an eavesdropper and monitoring the quality of their communication, Alice and Bob can detect any disruptions or irregularities that may indicate the involvement of a third party and take appropriate measures to safeguard their entangled communication.