6 across. A banned substance commonly found among stars, and not just stars of track and field!
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42 across. Even a part of My Lovely Horse wastes away. ??t?e?n (7).
48 across. Private beliefs that lack constant content can reduce us to tears if they're being worked on. ??i?n? (6).
64 down. You'll be very interested to learn about Wounded Knee; a biblical underdog was beheaded also. K??? (4).