1…My saintly paternal grandmother the Rebbetzin2 told us that a certain agunah once came to her father-in-law, the saintly Rebbe [the Tzemach Tzedek]. She brought along her son, who was a lad of eleven or twelve. The boy was totally mute, and also hard of hearing.
This was during the time when agunos were only permitted to enter the antechamber, while the door [to the Rebbe’s room] remained open. The Rebbe would sit there and listen to each one’s petition and history. Then, he would reply to the attendant Reb Chayim Dov,3 “Tell her to travel to such-and-such place” or “tell her to consult Rabbi so-and-so,” etc.
This agunah would come to the Rebbe several times a week, bringing her son. At the same time, she would bring food.4 Several weeks passed, but so many people had come that her turn to enter had not yet arrived.
Once, she placed her son under the table in the minyan room where the Rebbe received people for yechidus, cautioning him that when the Rebbe began to receive people, he should rise from his hiding place and hand the Rebbe her petition. The lad followed his mother’s instructions, and sat under the table, hidden by the table cloth and unseen by anyone.
The procedure was that the attendant would stand near the table, while the other attendant Reb Elia Leib5 would assign the order in which the chassidim were to enter. Suddenly, the lad emerged from his hiding place. The attendant became very angry and shouted, “Sheigetz!”
To this, the Rebbe replied, “Simple faith lights up the eyes; greatness is given to certain individuals only for the good of the Jewish people.”6
He then turned to the lad and uttered the following holy words: “Go and tell your mother that your father is alive. She should travel to Denenburg.”

My grandmother related:

This agunah had been sitting in my home and weeping about her misfortune. Her husband had been missing for seven years. Now, several rabbis had given her permission to remarry, on condition that the Rebbe agreed.7
Suddenly, her son entered and cried out in a loud voice, “The Rebbe told me to tell Mother that Father is alive, and that she should travel to Denenburg.” At this, the agunah fainted.
This double miracle8 caused a great commotion. But my mother-in-law9 remarked:
“Just look at what everyone’s gotten so excited about! At my father’s10 and my grandfather’s11 court, miracles lay scattered about, and no one bothered to pick them up. Just look what’s happening, and what’s caused so much excitement! Grandfather said that he would prefer it if people understood Chassidus. As for getting excited over miracles, we leave that for [the chassidim of] Vohlynia!”12