Complex sentence: Confused, she confronts Tōma when he returns to Academy City in the 16th novel; she is relieved that Tōma still remembers the incident with Accelerator and the Sisters.
Split into simpler sentences: Confused, she confronts Tōma when he returns to Academy City in the 16th novel. Though, she is relief that Tōma still remembers the incident with Accelerator and the Sisters.