Klein ISD police say a second student, 16-year-old Noah Lewis, is missing from Klein Collins High School.
Sophomore Alyssa Schaefer, 15, was last seen across the street from the school on Monday, but did not return home on the bus as expected.
Investigators now say Lewis fits the description of the unidentified boy Schaefer was seen speaking with shortly before her disappearance.
Law enforcement are now working with a canine to assess the search area.
"All leads are being investigated at this time," said Klein ISD spokesperson Judy Rimato. "We want to ask for the public's help in locating these two missing teens and we appreciate any support the community can give us to get their safe return."
While Klein ISD officials are not classifying either as student as a runaway, Eyewitness News has learned Schaefer was allegedly seen with Lewis yesterday afternoon and that she had asked a friend if they could come over.
Officers have not said, however, that the two are together. They say they have no information about any possible relationship between the teens.
Alyssa's mother, Victoria Schaefer, told Eyewitness News she has heard Lewis stays at the home of another boy in the area.
"We've created a grid and we're working neighborhood by neighborhood with patrols looking for them, working any known locations where people might hide," explained Klein ISD Police Chief David Kimberly.
K9 and helicopter patrols have been brought in to assist in the search.
Victoria Schaefer returned to the scene of her daughter's last known whereabouts this morning to make a tearful plea for the sophomore's return.
"Everybody is so worried about you, we want you to come home," Victoria said. "You're not in trouble, I just want to give you a great big hug and hold you... Please be safe."
Right now, family and friends are looking for any clues they can, even trying to hack into her social media accounts.
MISSING KLEIN COLLINS STUDENT: 15-year-old Alyssa Schafer did not return home this afternoon. If you have any... https://t.co/kwRfYMJpiL— Klein ISD Police (@kleinisdpd) October 18, 2016
Her mother said the last time she saw her daughter was Sunday night, as she kissed the 15-year-old before they went to bed.
On Monday morning, Alyssa got up by herself and got off to school, a normal routine for their family, now wondering where she has gone.
Her mother says she was last seen wearing black leggings, black boots and a red flannel shirt. She has pink bands on her braces, Victoria Schaefer says.
Anyone with information is asked to call the Harris County Sheriff's Office at 713-221-6000.