Philip and Sophia Macht (plaintiffs) owned property in Baltimore subject to a lease of airspace rights to the neighboring Blaustein Building. The lease was for 98 years and nine months at a rent equal to twice the Machts’ real estate taxes for their entire property, including “land, improvements and airspace.” The Department of Assessments of Baltimore City (defendant) valued the Machts’ airspace at $50,700, and assessed the airspace separately from the Machts’ surface land for tax purposes. The Machts appealed, and the Baltimore Board of Municipal Zoning Appeals vacated the assessment. The Maryland Tax Court reinstated the assessment. The Machts appealed.