0030 hrs I was standing in my back yard in Ellenbrook Perth smoking a cigarette. The weather conditions that night was a high alt. overcast with little to no wind and no rain. The eastern horizon was clear above the hills that run N/S along Perth area. A flashing light came into view about four(4) km in distance east of my house moving N at approx. 500 meters altitude with a speed no more than 20 knots. I thought it was a light aircraft leaving the airport because it was flying right in the glide path of the airport except it was flying the wrong way. Every night I observe at least ten to twenty airliners making final approach south towards the airport but this "aircraft" was immediately suspicious to me as it was flying N. Being a Sunday night/ Monday morning there had not been any airliners on approach for some hours. The skies in the area were completely empty of traffic. Flying slowly N at about 20 knots the flashing light suddenly stopped and hovered for a minute or two flashing rapidly, white and red. It would also seem to emit no light at all. It seemed to have three modes of light, white, red and no light. When it was not flashing light I could make out a metallic object approx. 3 to 5 meters in length in the shape of a capsule. Due to the cloud cover I could tell it was metallic against the dark rain clouds. The object then became more rapid in its flashing and began to dart randomly in the sky through all axes. The object continued in this way for maybe five minutes until it dived at startling speed to tree level approx three(3) km from my house. At tree level the object only emitted white light and proceeded to fly rapidly through the trees N to S i.e to my left and right. It did not however seem to actually illuminate the immediate vicinity i.e the trees and ground. The object then ascended instantly to its previous alt. resuming its previous movement and flashing pattern. It was at this point I heard what sounded like a prop driven light aircraft approaching the area from the SW but could not see it coming due to my house blocking the view of the sky in that direction. Scanning the sky intently trying to locate the incoming aircraft the noise steadily increased in volume until the noise broke over my house and made me look directly up. I observed a pulsating red light flying at 100 meters alt. at about ten knots moving directly over my house in a straight path of flight in a northerly direction. The red light was apparently attached to the underside of an unknown flying vehicle. The vehicle itself was completely transparent. After about fifty to one hundred meters of flying in a straight line path over my house the vehicle made a gentle left hand turn heading NW and at this point I lost sight of it behind the neighbors house but could still hear the noise it was making. Apparently the flashing light had disappeared while this vehicle had flown over because the sky was empty after I lost sight of the second object.Notes and Conclusions. 1.The flashing lights on the first object appeared to be a single source and not eminating from different parts of the object. 2.The noise signature on the second object was very distinct. There seemed to be no air intake whatsoever. The noise was like a deep vibration. 3.Due to the very low airspeed of the second object it could not have been a prop driven aircraft and neither was there any rotor wash in the case of a helicopter. 4.Apart from the pulsating red light there were no other navigation lights on the second object. 5.The two objects were likely not to be two random events coinciding but were related to one another.