As his son, Ken, wheels him up the concrete ramp and through the doors, Lindsey's grin says it all.
Lindsey smiles as his sone wheels him up the ramp and into his old high school. 
mnli hypothesis: Lindsey smiles as his sone wheels him up the ramp and into his old high school.  premise: As his son, Ken, wheels him up the concrete ramp and through the doors, Lindsey's grin says it all.