Create a poignant and evocative illustration that explores the deeper, more melancholic aspects of love. Set the scene in a dimly lit, abandoned room, with a single, faded love letter lying on a dusty table, surrounded by wilted flowers and a forgotten locket. Use a moody color palette of deep blues, purples, and grays to convey a sense of loss and longing. Include a solitary figure standing by a rain-streaked window, gazing out at a stormy landscape, with a distant, sorrowful expression. Add symbolic elements such as a broken hourglass, a dying candle, and a empty birdcage to emphasize the passage of time and the absence of a beloved companion. Complete the scene with a soft, ethereal glow that hints at memories of happier times, and include a subtle banner with the words 'Love's Echo' in a delicate, handwritten font