What is wrong with my code?

namespace Treehouse.CodeChallenges
{
    class RepeatDetector : SequenceDetector
    {
         public override string Description {get;}="Detects repetitions";
        public override bool Scan(int[] sequence)
        {
            if(sequence.Length < 2)
            {
                return false;
            }

            for(int i = 1; i < sequence.Length; ++i)
            {
                if(sequence[i] == sequence[i-1])
                {
                    return Description;
                }
            }

            return false;
        }
    }
}

namespace Treehouse.CodeChallenges
{
    class SequenceDetector
    {
        public virtual string Description {get;}= "";

        public virtual bool Scan(int[] sequence)
        {
            return true;
        }
    }
}