// Load index and skip more if feasible.
	if partSkip > 0 && len(oi.Parts) > firstPartIdx && len(oi.Parts[firstPartIdx].Index) > 0 {
		_, isEncrypted := crypto.IsEncrypted(oi.UserDefined)
		if isEncrypted {
			dec, err := decrypt(oi.Parts[firstPartIdx].Index)
			if err == nil {
				// Load Index
				var idx s2.Index
				_, err := idx.Load(s2.RestoreIndexHeaders(dec))

				// Find compressed/uncompressed offsets of our partskip